arch: Add support for RX GCC build

This commit only add minimal require part to enable Renesas
RX architecture gcc toolchain build on Zephyr SDK

Signed-off-by: Duy Nguyen <[email protected]>

Author: duynguyenxa

cmake/zephyr/target.cmake

@@ -10,6 +10,7 @@ set(CROSS_COMPILE_TARGET_arm64   aarch64-zephyr-elf)
 set(CROSS_COMPILE_TARGET_nios2     nios2-zephyr-elf)
 set(CROSS_COMPILE_TARGET_riscv   riscv64-zephyr-elf)
 set(CROSS_COMPILE_TARGET_mips       mips-zephyr-elf)
+set(CROSS_COMPILE_TARGET_rx           rx-zephyr-elf)
 set(CROSS_COMPILE_TARGET_microblaze microblazeel-zephyr-elf)
 set(CROSS_COMPILE_TARGET_xtensa   xtensa-${SOC_TOOLCHAIN_NAME}_zephyr-elf)
 

configs/rx-zephyr-elf.config

@@ -0,0 +1,6 @@
+CT_CONFIG_VERSION="3"
+CT_EXPERIMENTAL=y
+CT_ARCH_RX=y
+CT_TARGET_CFLAGS="-ftls-model=local-exec"
+CT_TARGET_VENDOR="zephyr"
+CT_MULTILIB=y