[ARM] 3194/1: add pfn_to_kaddr macro for ARM take2

Patch from Hiroki Kaminaga

This patch defines a new macro: pfn_to_kaddr(pfn).
Same macro is already defined on other arch, such as i386.
Signed-off-by: NHiroki Kaminaga <kaminaga@sm.sony.co.jp>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

include/asm-arm/memory.h

@@ -122,6 +122,7 @@ static inline void *phys_to_virt(unsigned long x)
  */
 #define __pa(x)			__virt_to_phys((unsigned long)(x))
 #define __va(x)			((void *)__phys_to_virt((unsigned long)(x)))
+#define pfn_to_kaddr(pfn)	__va((pfn) << PAGE_SHIFT)
 
 /*
  * Virtual <-> DMA view memory address translations