Remove '#' from immediate parameter in AARCH64 inline assembly in mmu.

This code now works with both gcc and clang.
Signed-off-by: NMark Charlebois <charlebm@gmail.com>
Signed-off-by: NBehan Webster <behanw@converseincode.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>