arm64: allow vmalloc regions to be set with set_memory_*

arm64: allow vmalloc regions to be set with set_memory_*

The range of set_memory_* is currently restricted to the module address
range because of difficulties in breaking down larger block sizes.
vmalloc maps PAGE_SIZE pages so it is safe to use as well. Update the
function ranges and add a comment explaining why the range is restricted
the way it is.

Suggested-by: Laura Abbott <labbott@fedoraproject.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 95f5c80050ad723163aa80dc8bffd48ef4afc6d5)
Signed-off-by: Alex Shi <alex.shi@linaro.org>