All of our current EC configs have RO and a single RW image. Calling
that image 'A' is confusing, particularly when combined with EC
software sync (where the RW image is updated from either the A or B AP
RW firmware). So, rename it.
This changes all the build artifacts and constants. Internal EC
commands and host commands still refer to A/B; that will be fixed in
part 2.
BUG=none
TEST=build link, snow, bds
Change-Id: Icfed4914745f0799bb71befb6a6563cfd8bc90ab
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/27649
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>