ARM: mm: fix reporting of read-only PMD bits

On non-LPAE ARMv6+, read-only PMD bits are defined with the combination
"PMD_SECT_APX | PMD_SECT_AP_WRITE". Adjusted the bit masks to correctly
report this.

Change-Id: I96f64eea038f9464bb0122b82172838181e4f201
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Git-commit: fff00db852f2ff0faf5f539b5e28ac498fc007f8
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Laura Abbott <lauraa@codeaurora.org>