keyboard_8042: Allow scancode sets to be mutable

Add an option to allow the scancode sets to be mutable.  The only
reason to use this is to allow a scancode to be changed at runtime,
for instance to support different keyboards in one image.

The side effect of this is the scancode sets are moved out of the
shared RO section.

BUG=b:36735408
BRANCH=none
TEST=make -j buildall

Change-Id: Iefb97691d1f295411d7b5db603d9214d41af49fd
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://chromium-review.googlesource.com/506717
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@chromium.org>
3 files changed