ARM: decompressor: Flush tlb before swiching domain 0 to client mode

If the bootloader used a page table that is incompatible with domain 0
in client mode, and boots with the mmu on, then swithing domain 0 to
client mode causes a fault if we don't flush the tlb after updating
the page table pointer.

v2: Add ISB before loading dacr.

Signed-off-by: Arve Hjønnevåg <arve@android.com>

arch/arm/boot/compressed/head.S

@@ -717,6 +717,8 @@ __armv7_mmu_cache_on:
 		bic     r6, r6, #1 << 31        @ 32-bit translation system
 		bic     r6, r6, #3 << 0         @ use only ttbr0
 		mcrne	p15, 0, r3, c2, c0, 0	@ load page table pointer
+		mcrne	p15, 0, r0, c8, c7, 0	@ flush I,D TLBs
+		mcr	p15, 0, r0, c7, c5, 4	@ ISB
 		mcrne	p15, 0, r1, c3, c0, 0	@ load domain access control
 		mcrne   p15, 0, r6, c2, c0, 2   @ load ttb control
 #endif