Documentation: arm64 also supports disable hugeiomap

arm64 also supports disable hugeiomap,updated documentation.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Link: https://lore.kernel.org/r/1599740386-47210-1-git-send-email-tiantao6@hisilicon.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/kernel-parameters.txt

@@ -3188,7 +3188,7 @@
 			register save and restore. The kernel will only save
 			legacy floating-point registers on task switch.
 
-	nohugeiomap	[KNL,X86,PPC] Disable kernel huge I/O mappings.
+	nohugeiomap	[KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
 
 	nosmt		[KNL,S390] Disable symmetric multithreading (SMT).
 			Equivalent to smt=1.