arm64 Kconfig: select gigantic page

Arm64 supports gigantic pages after commit 084bd29 ("ARM64: mm:
HugeTLB support.") however, it can only be allocated at boottime and
can't be freed.

This patch selects ARCH_HAS_GIGANTIC_PAGE to make gigantic pages can be
allocated and freed at runtime for arch arm64.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Yisheng Xie <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Hillf Danton <[email protected]>
Cc: Hanjun Guo <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Sudeep Holla <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Yisheng Xie

arch/arm64/Kconfig

@@ -11,6 +11,7 @@ config ARM64
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_GIGANTIC_PAGE
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST