[XTENSA] Add typecast macro for constants

Add macros (__XTENSA_UL and __XTENSA_UL_CONST) for typecasting
constants.
Signed-off-by: Chris Zankel <chris@zankel.net>

include/asm-xtensa/processor.h

@@ -33,7 +33,7 @@
  * the 1 GB requirement applies to the stack as well.
  */
 
-#define TASK_SIZE	0x40000000
+#define TASK_SIZE	__XTENSA_UL_CONST(0x40000000)
 
 /*
  * General exception cause assigned to debug exceptions. Debug exceptions go

include/asm-xtensa/types.h

@@ -11,6 +11,15 @@
 #ifndef _XTENSA_TYPES_H
 #define _XTENSA_TYPES_H
 
+
+#ifdef __ASSEMBLY__
+# define __XTENSA_UL(x)		(x)
+# define __XTENSA_UL_CONST(x)	x
+#else
+# define __XTENSA_UL(x)		((unsigned long)(x))
+# define __XTENSA_UL_CONST(x)	x##UL
+#endif
+
 #ifndef __ASSEMBLY__
 
 typedef unsigned short umode_t;