ARM: 9247/1: mm: set readonly for MT_MEMORY_RO with ARM_LPAE

MT_MEMORY_RO is introduced by commit 598f0a99fa ("ARM: 9210/1:
Mark the FDT_FIXED sections as shareable"), which is a readonly
memory type for FDT area, but there are some different between
ARM_LPAE and non-ARM_LPAE, we need to setup PMD_SECT_AP2 and
L_PMD_SECT_RDONLY for MT_MEMORY_RO when ARM_LAPE enabled.

non-ARM_LPAE	0xff800000-0xffa00000           2M PGD KERNEL      ro NX SHD
ARM_LPAE	0xff800000-0xffc00000           4M PMD RW NX SHD
ARM_LPAE+fix	0xff800000-0xffc00000           4M PMD ro NX SHD

Fixes: 598f0a99fa ("ARM: 9210/1: Mark the FDT_FIXED sections as shareable")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arch/arm/mm/mmu.c

@@ -300,7 +300,11 @@ static struct mem_type mem_types[] __ro_after_init = {
 		.prot_pte  = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
 			     L_PTE_XN | L_PTE_RDONLY,
 		.prot_l1   = PMD_TYPE_TABLE,
+#ifdef CONFIG_ARM_LPAE
+		.prot_sect = PMD_TYPE_SECT | L_PMD_SECT_RDONLY | PMD_SECT_AP2,
+#else
 		.prot_sect = PMD_TYPE_SECT,
+#endif
 		.domain    = DOMAIN_KERNEL,
 	},
 	[MT_ROM] = {