ARM: 8736/1: mm: dump: make the page table dumping seq_file

This patch makes the page table dumping seq_file optional.
It makes the page table dumping code usable for other cases.

This patch refers below commit of arm64.
(ae5d1cf3
("arm64: dump: Make the page table dumping seq_file optional"))

Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>