unicore32: delete specified xlate_dev_mem_ptr

For the commit <f1ecc698> has changed
xlate_dev_mem_ptr definition in asm-generic/io.h for the systems with
an MMU, so delete it from unicore32 specified io.h.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jonas Bonn <jonas@southpole.se>

arch/unicore32/include/asm/io.h

@@ -39,13 +39,6 @@ extern void __uc32_iounmap(volatile void __iomem *addr);
 #define ioremap_cached(cookie, size)	__uc32_ioremap_cached(cookie, size)
 #define iounmap(cookie)			__uc32_iounmap(cookie)
 
-/*
- * Convert a physical pointer to a virtual kernel pointer for /dev/mem
- * access
- */
-#undef xlate_dev_mem_ptr
-#define xlate_dev_mem_ptr(p)	__va(p)
-
 #define HAVE_ARCH_PIO_SIZE
 #define PIO_OFFSET		(unsigned int)(PCI_IOBASE)
 #define PIO_MASK		(unsigned int)(IO_SPACE_LIMIT)