simplify invocations of change_timer_flipflop method

by passing it directly the operation values instead of explicitly
interpreting their meaning on the calling end.

(Addressing "it feels like it's always used with constant parameters"
comment from mamedev#13220 (comment))

src/devices/cpu/tlcs900/tmp94c241.cpp

@@ -711,31 +711,8 @@ void tmp94c241_device::change_timer_flipflop(uint8_t flipflop, uint8_t operation
 
 void tmp94c241_device::t02ffcr_w(uint8_t data)
 {
-	switch( data & 0x0c )
-	{
-	case 0x00:
-		change_timer_flipflop( 1, FF_INVERT );
-		break;
-	case 0x04:
-		change_timer_flipflop( 1, FF_SET );
-		break;
-	case 0x08:
-		change_timer_flipflop( 1, FF_CLEAR );
-		break;
-	}
-	switch( data & 0xc0 )
-	{
-	case 0x00:
-		change_timer_flipflop( 3, FF_INVERT );
-		break;
-	case 0x40:
-		change_timer_flipflop( 3, FF_SET );
-		break;
-	case 0x80:
-		change_timer_flipflop( 3, FF_CLEAR );
-		break;
-	}
-
+	change_timer_flipflop( 1, (data >> 2) & 3 );
+	change_timer_flipflop( 3, (data >> 6) & 3 );
 	SFR_T02FFCR = data | 0xcc;
 }
 
@@ -854,103 +831,33 @@ uint8_t tmp94c241_device::t4ffcr_r()
 
 void tmp94c241_device::t4ffcr_w(uint8_t data)
 {
-	switch( data & 0x03 )
-	{
-	case 0x00:
-		change_timer_flipflop( 4, FF_INVERT );
-		break;
-	case 0x01:
-		change_timer_flipflop( 4, FF_SET );
-		break;
-	case 0x02:
-		change_timer_flipflop( 4, FF_CLEAR );
-		break;
-	}
-	switch( data & 0xc0 )
-	{
-	case 0x00:
-		change_timer_flipflop( 5, FF_INVERT );
-		break;
-	case 0x40:
-		change_timer_flipflop( 5, FF_SET );
-		break;
-	case 0x80:
-		change_timer_flipflop( 5, FF_CLEAR );
-		break;
-	}
-
+	change_timer_flipflop( 4, data & 3 );
+	change_timer_flipflop( 5, (data >> 6) & 3 );
 	SFR_T4FFCR = data | 0xc3;
 }
 
-uint8_t tmp94c241_device::t8ffcr_r()
+uint8_t tmp94c241_device::t6ffcr_r()
 {
-	return SFR_T8FFCR;
+	return SFR_T6FFCR;
 }
 
-void tmp94c241_device::t8ffcr_w(uint8_t data)
+void tmp94c241_device::t6ffcr_w(uint8_t data)
 {
-	switch( data & 0x03 )
-	{
-	case 0x00:
-		change_timer_flipflop( 8, FF_INVERT );
-		break;
-	case 0x01:
-		change_timer_flipflop( 8, FF_SET );
-		break;
-	case 0x02:
-		change_timer_flipflop( 8, FF_CLEAR );
-		break;
-	}
-	switch( data & 0xc0 )
-	{
-	case 0x00:
-		change_timer_flipflop( 9, FF_INVERT );
-		break;
-	case 0x40:
-		change_timer_flipflop( 9, FF_SET );
-		break;
-	case 0x80:
-		change_timer_flipflop( 9, FF_CLEAR );
-		break;
-	}
-
-	SFR_T8FFCR = data | 0xc3;
+	change_timer_flipflop( 6, data & 3 );
+	change_timer_flipflop( 7, (data >> 6) & 3 );
+	SFR_T6FFCR = data | 0xc3;
 }
 
-
-uint8_t tmp94c241_device::t6ffcr_r()
+uint8_t tmp94c241_device::t8ffcr_r()
 {
-	return SFR_T6FFCR;
+	return SFR_T8FFCR;
 }
 
-void tmp94c241_device::t6ffcr_w(uint8_t data)
+void tmp94c241_device::t8ffcr_w(uint8_t data)
 {
-	switch( data & 0x03 )
-	{
-	case 0x00:
-		change_timer_flipflop( 6, FF_INVERT );
-		break;
-	case 0x01:
-		change_timer_flipflop( 6, FF_SET );
-		break;
-	case 0x02:
-		change_timer_flipflop( 6, FF_CLEAR );
-		break;
-	}
-	switch( data & 0xc0 )
-	{
-	case 0x00:
-		change_timer_flipflop( 7, FF_INVERT );
-		break;
-	case 0x40:
-		change_timer_flipflop( 7, FF_SET );
-		break;
-	case 0x80:
-		change_timer_flipflop( 7, FF_CLEAR );
-		break;
-	}
-
-	SFR_T6FFCR = data | 0xc3;
+	change_timer_flipflop( 8, data & 3 );
+	change_timer_flipflop( 9, (data >> 6) & 3 );
+	SFR_T8FFCR = data | 0xc3;
 }
 
 uint8_t tmp94c241_device::taffcr_r()
@@ -960,31 +867,8 @@ uint8_t tmp94c241_device::taffcr_r()
 
 void tmp94c241_device::taffcr_w(uint8_t data)
 {
-	switch( data & 0x03 )
-	{
-	case 0x00:
-		change_timer_flipflop( 0xa, FF_INVERT );
-		break;
-	case 0x01:
-		change_timer_flipflop( 0xa, FF_SET );
-		break;
-	case 0x02:
-		change_timer_flipflop( 0xa, FF_CLEAR );
-		break;
-	}
-	switch( data & 0xc0 )
-	{
-	case 0x00:
-		change_timer_flipflop( 0xb, FF_INVERT );
-		break;
-	case 0x40:
-		change_timer_flipflop( 0xb, FF_SET );
-		break;
-	case 0x80:
-		change_timer_flipflop( 0xb, FF_CLEAR );
-		break;
-	}
-
+	change_timer_flipflop( 0xa, data & 3 );
+	change_timer_flipflop( 0xb, (data >> 6) & 3 );
 	SFR_TAFFCR = data | 0xc3;
 }