Add a portNOP() implementation and relax the stack alignment requirements in the IAR MSP430X port layer.

Source/portable/IAR/MSP430X/portmacro.h

@@ -141,10 +141,10 @@ extern void vPortYield( void );
 /*-----------------------------------------------------------*/
 
 /* Hardware specifics. */
-#define portBYTE_ALIGNMENT			4
+#define portBYTE_ALIGNMENT			2
 #define portSTACK_GROWTH			( -1 )
 #define portTICK_RATE_MS			( ( portTickType ) 1000 / configTICK_RATE_HZ )	
-#define portNOP()	
+#define portNOP()					__no_operation()
 /*-----------------------------------------------------------*/
 
 /* Task function macros as described on the FreeRTOS.org WEB site. */