ARM: 7652/1: mm: fix missing use of 'asid' to get asid value from mm->context.id

Fix missing use of the asid macro when getting the ASID from the mm->context.id field.
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/proc-v7-3level.S

@@ -48,7 +48,7 @@
 ENTRY(cpu_v7_switch_mm)
 #ifdef CONFIG_MMU
 	mmid	r1, r1				@ get mm->context.id
-	and	r3, r1, #0xff
+	asid	r3, r1
 	mov	r3, r3, lsl #(48 - 32)		@ ASID
 	mcrr	p15, 0, r0, r3, c2		@ set TTB 0
 	isb