arm64: support huge vmalloc mappings

As commit 559089e0 ("vmalloc: replace VM_NO_HUGE_VMAP with
VM_ALLOW_HUGE_VMAP"), the use of hugepage mappings for vmalloc
is an opt-in strategy, so it is saftly to support huge vmalloc
mappings on arm64, for now, it is used in kvmalloc() and
alloc_large_system_hash().
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20220911044423.139229-1-wangkefeng.wang@huawei.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -3614,7 +3614,7 @@
 
 	nohugeiomap	[KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
 
-	nohugevmalloc	[PPC] Disable kernel huge vmalloc mappings.
+	nohugevmalloc	[KNL,X86,PPC,ARM64] Disable kernel huge vmalloc mappings.
 
 	nosmt		[KNL,S390] Disable symmetric multithreading (SMT).
 			Equivalent to smt=1.

arch/arm64/Kconfig

@@ -149,6 +149,7 @@ config ARM64
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_BITREVERSE
 	select HAVE_ARCH_COMPILER_H
+	select HAVE_ARCH_HUGE_VMALLOC
 	select HAVE_ARCH_HUGE_VMAP
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_JUMP_LABEL_RELATIVE