tests: dac: frdm_mcxa156: add dac test support

add frdm_mcxa156 defines in source

Signed-off-by: Neil Chen <[email protected]>

Author: NeilChen93

tests/drivers/dac/dac_api/src/test_dac.c

@@ -48,6 +48,7 @@
 	defined(CONFIG_BOARD_FRDM_K64F) || \
 	defined(CONFIG_BOARD_FRDM_K22F) || \
 	defined(CONFIG_BOARD_FRDM_MCXN947) || \
+	defined(CONFIG_BOARD_FRDM_MCXA156) || \
 	defined(CONFIG_BOARD_SEEEDUINO_XIAO) || \
 	defined(CONFIG_BOARD_ARDUINO_MKRZERO) || \
 	defined(CONFIG_BOARD_ARDUINO_ZERO) || \