ARM: 6605/1: Add missing include "asm/memory.h"

This patch fixes below build error by adding the missing asm/memory.h,
which is needed for arch_is_coherent().

$ make pxa3xx_defconfig; make
CC init/do_mounts_rd.o
In file included from include/linux/list_bl.h:5,
from include/linux/rculist_bl.h:7,
from include/linux/dcache.h:7,
from include/linux/fs.h:381,
from init/do_mounts_rd.c:3:
include/linux/bit_spinlock.h: In function 'bit_spin_unlock':
include/linux/bit_spinlock.h:61: error: implicit declaration of function 'arch_is_coherent'
make[1]: *** [init/do_mounts_rd.o] Error 1
make: *** [init] Error 2

Signed-off-by: Axel Lin <[e-mail]>
Acked-by: Peter Huewe <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/include/asm/system.h

···
 #define rmb()		dmb()
 #define wmb()		mb()
 #else
+#include <asm/memory.h>
 #define mb()	do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
 #define rmb()	do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)
 #define wmb()	do { if (arch_is_coherent()) dmb(); else barrier(); } while (0)