boards: lpcxpresso55s69: merge dual core images

Merges cpu0 and cpu1 targets to a single image, named multicore.bin,
this image can be found in the build folder.
Documentation is to be updated in a later commit.

Signed-off-by: Andrei Gansari <andrei.gansari@nxp.com>

boards/arm/lpcxpresso55s69/CMakeLists.txt

@@ -98,3 +98,21 @@ if (CONFIG_BUILD_WITH_TFM)
 		)
 	endif()
 endif()
+
+if (CONFIG_SECOND_CORE_MCUX)
+	# Set srec_cat binary name
+	find_program(SREC_CAT srec_cat)
+	if(${SREC_CAT} STREQUAL SREC_CAT-NOTFOUND)
+		message(FATAL_ERROR "'srec_cat' not found. Please install it, or add it to $PATH.")
+	endif()
+
+	#merge cpu0 and cpu1 to a single image
+	#offset is taken from zephyr,code-cpu1-partition
+	set_property(GLOBAL APPEND PROPERTY extra_post_build_commands
+		COMMAND ${SREC_CAT}
+		ARGS ${CMAKE_BINARY_DIR}/zephyr/${KERNEL_BIN_NAME} -Binary
+			${REMOTE_ZEPHYR_DIR}/${KERNEL_BIN_NAME} -Binary
+			-offset ${CONFIG_SECOND_CORE_BOOT_ADDRESS_MCUX}
+			-o ${CMAKE_BINARY_DIR}/multicore.bin -Binary
+	)
+endif()