bootloader: fix build with CONFIG_CONSOLE_UART_NONE (GIT8266O-824)

[f00b4r0]

Setting CONFIG_CONSOLE_UART_NONE would trigger the following error:

ESP8266_RTOS_SDK/components/bootloader_support/src/bootloader_init.c: In function 'uart_console_configure':
ESP8266_RTOS_SDK/components/bootloader_support/src/bootloader_init.c:628:80:
  error: 'CONFIG_ESP_CONSOLE_UART_BAUDRATE' undeclared (first use in this function); did you mean 'CONFIG_ESP_CONSOLE_UART_NUM'?
     uart_div_modify(CONFIG_ESP_CONSOLE_UART_NUM, BOOTLOADER_CONSOLE_CLK_FREQ / CONFIG_ESP_CONSOLE_UART_BAUDRATE);
                                                                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                                                                CONFIG_ESP_CONSOLE_UART_NUM

This is because ESP8266_MODIFY_UART_BAUDRATE is unconditionally defined, even when CONFIG_CONSOLE_UART_NONE is set.

This commit fixes this.

[CLAassistant]

All committers have signed the CLA.

[f00b4r0]

FWIW even with CONFIG_CONSOLE_UART_NONE there's still output on UART0, probably related to the fact that components/esp_common/Kconfig defines ESP_CONSOLE_UART_NUM=0 when CONFIG_CONSOLE_UART_NONE is selected. Removing the symbol breaks build in gdbstub:

In file included from 
ESP8266_RTOS_SDK/components/esp8266/include/esp8266/uart_register.h:18,
                 from ESP8266_RTOS_SDK/components/esp_gdbstub/esp8266/gdbstub_esp8266.c:15:
ESP8266_RTOS_SDK/components/esp_gdbstub/esp8266/gdbstub_esp8266.c: In function 'esp_gdbstub_getchar':
ESP8266_RTOS_SDK/components/esp_gdbstub/esp8266/gdbstub_esp8266.c:20:18: error: 'CONFIG_ESP_CONSOLE_UART_NUM' undeclared (first use in this function); did you mean 'CONFIG_ESP_CONSOLE_UART_NONE'?
 #define UART_NUM CONFIG_ESP_CONSOLE_UART_NUM
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~

And that, even though GDB stub is not enabled:

grep GDB sdkconfig
# CONFIG_ESP_PANIC_GDBSTUB is not set

It seems completely disabling serial output isn't supported and would need more work; not sure if there's interest for this?

[Sonic-Amiga]

CONFIG_CONSOLE_UART_NONE there's still output on UART0

Could be output from wifi code using early boot-time console. I had to "plug" it with #1253