ARM: 6757/1: fix tlb.h induced linux/swap.h build failure

Commit

	06824ba8 (ARM: tlb: delay page freeing for SMP and ARMv7 CPUs)

introduced a build failure for builds with CONFIG_SWAP=n:

	In file included from arch/arm/mm/init.c:27:
	arch/arm/include/asm/tlb.h: In function 'tlb_flush_mmu':
	arch/arm/include/asm/tlb.h:101: error: implicit declaration of function 'release_pages'
	arch/arm/include/asm/tlb.h: In function 'tlb_remove_page':
	arch/arm/include/asm/tlb.h:165: error: implicit declaration of function 'page_cache_release'

as linux/swap.h doesn't include linux/pagemap.h but actually needs it
(see comments in linux/swap.h as to why this is.)

Fix that by #including <linux/pagemap.h> in <asm/pgalloc.h> as it's done
by x86.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/pgalloc.h

@@ -10,6 +10,8 @@
 #ifndef _ASMARM_PGALLOC_H
 #define _ASMARM_PGALLOC_H
 
+#include <linux/pagemap.h>
+
 #include <asm/domain.h>
 #include <asm/pgtable-hwdef.h>
 #include <asm/processor.h>