ARM: 7436/1: Do not map the vectors page as write-through on UP systems

The vectors page has been traditionally mapped as WT on UP systems but
this creates a mismatched alias with the directly mapped RAM that is
using WB attributes. On newer processors like Cortex-A15 this has
implications on the data/instructions coherency at the point of
unification (usually L2).

This patch removes such restriction.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/mmu.c

@@ -421,12 +421,6 @@ static void __init build_mem_type_table(void)
 	cp = &cache_policies[cachepolicy];
 	vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
 
-	/*
-	 * Only use write-through for non-SMP systems
-	 */
-	if (!is_smp() && cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH)
-		vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte;
-
 	/*
 	 * Enable CPU-specific coherency if supported.
 	 * (Only available on XSC3 at the moment.)