ARM: mm: Transparent huge page support for LPAE systems.

The patch adds support for THP (transparent huge pages) to LPAE
systems. When this feature is enabled, the kernel tries to map
anonymous pages as 2MB sections where possible.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[steve.capper@linaro.org: symbolic constants used, value of
PMD_SECT_SPLITTING adjusted, tlbflush.h included in pgtable.h,
added PROT_NONE support.]
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 860f034..f07a462 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1711,6 +1711,10 @@
        def_bool y
        depends on ARM_LPAE
 
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE
+       def_bool y
+       depends on ARM_LPAE
+
 source "mm/Kconfig"
 
 config FORCE_MAX_ZONEORDER