Fix the ARMv6 CPU id in compressed/head.S

This code was still using the old format for the ARMv6 CPU id and it wasn't
flushing the caches on the MPCore CPU (and other ARM1176 cores). The patch
changes the mask bits to cope with the new id format.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm/boot/compressed/head.S

@@ -605,8 +605,8 @@ proc_types:
 		b	__armv4_mmu_cache_off
 		b	__armv4_mmu_cache_flush
 
-		.word	0x00070000		@ ARMv6
-		.word	0x000f0000
+		.word	0x0007b000		@ ARMv6
+		.word	0x0007f000
 		b	__armv4_mmu_cache_on
 		b	__armv4_mmu_cache_off
 		b	__armv6_mmu_cache_flush