m68k: Use asm-generic/io.h

Convert the m68k architecture to make use of the new asm-generic/io.h to
provide address mapping functions. As the generic implementations are
suitable for m68k this is primarily a matter of emoving code.

Feedback from architecture maintainers is welcome.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Huan Wang <alison.wang@freescale.com>
Cc: Angelo Dureghello <angelo@sysam.it>
Acked-by: Angelo Dureghello <angelo@sysam.it>
Tested-by: Angelo Dureghello <angelo@sysam.it>

arch/m68k/include/asm/io.h

@@ -253,33 +253,6 @@ static inline void sync(void)
 	 */
 }
 
-/*
- * Given a physical address and a length, return a virtual address
- * that can be used to access the memory range with the caching
- * properties specified by "flags".
- */
-#define MAP_NOCACHE	(0)
-#define MAP_WRCOMBINE	(0)
-#define MAP_WRBACK	(0)
-#define MAP_WRTHROUGH	(0)
-
-static inline void *map_physmem(phys_addr_t paddr, unsigned long len,
-				unsigned long flags)
-{
-	return (void *)paddr;
-}
-
-/*
- * Take down a mapping set up by map_physmem().
- */
-static inline void unmap_physmem(void *vaddr, unsigned long flags)
-{
-
-}
-
-static inline phys_addr_t virt_to_phys(void * vaddr)
-{
-	return (phys_addr_t)(vaddr);
-}
+#include <asm-generic/io.h>
 
 #endif				/* __ASM_M68K_IO_H__ */