lib: posix: Update attribute packed for posix_thread_attr

Add attributed packed for struct posix_thread_attr when arch is RX

Signed-off-by: Minh Tang <minh.tang.ue@bp.renesas.com>

Author: Minh Tang

lib/posix/options/posix_internal.h

@@ -22,11 +22,16 @@
  */
 #define PTHREAD_OBJ_MASK_INIT 0x80000000
 
-struct posix_thread_attr {
+#ifdef CONFIG_RX
+struct __packed posix_thread_attr
+#else
+struct posix_thread_attr
+#endif
+{
 	void *stack;
 	/* the following two bitfields should combine to be 32-bits in size */
-	uint32_t stacksize : CONFIG_POSIX_PTHREAD_ATTR_STACKSIZE_BITS;
-	uint16_t guardsize : CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS;
+	uint32_t stacksize: CONFIG_POSIX_PTHREAD_ATTR_STACKSIZE_BITS;
+	uint16_t guardsize: CONFIG_POSIX_PTHREAD_ATTR_GUARDSIZE_BITS;
 	int8_t priority;
 	uint8_t schedpolicy: 2;
 	bool contentionscope: 1;