ARM: pm: some ARMv7 requires a dsb in resume to ensure correctness

Add a dsb after the isb to ensure that the previous writes to the
CP15 registers take effect before we enable the MMU.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index dec72ee..a773f4e 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -255,6 +255,7 @@
 	mcr	p15, 0, r4, c10, c2, 0	@ write PRRR
 	mcr	p15, 0, r5, c10, c2, 1	@ write NMRR
 	isb
+	dsb
 	mov	r0, r9			@ control register
 	mov	r2, r7, lsr #14		@ get TTB0 base
 	mov	r2, r2, lsl #14