ARM: 7418/1: LPAE: fix access flag setup in mem_type_table

A zero value for prot_sect in the memory types table implies that
section mappings should never be created for the memory type in question.
This is checked for in alloc_init_section().

With LPAE, we set a bit to mask access flag faults for kernel mappings.
This breaks the aforementioned (!prot_sect) check in alloc_init_section().

This patch fixes this bug by first checking for a non-zero
prot_sect before setting the PMD_SECT_AF flag.
Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mm/mmu.c

@@ -489,6 +489,7 @@ static void __init build_mem_type_table(void)
 	 */
 	for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
 		mem_types[i].prot_pte |= PTE_EXT_AF;
+		if (mem_types[i].prot_sect)
 			mem_types[i].prot_sect |= PMD_SECT_AF;
 	}
 	kern_pgprot |= PTE_EXT_AF;