symbols: Don't declare symbols as const that don't describe const areas

Declaring the right thing in the first place helps avoid a bunch of
pointless casts. (Not all of these make necessarily sense to write, but
since we sometimes access a symbol to write behind that area or
something like that, it's easier to mark them all mutable than to
individually decide const/not-const for every symbol.)

BRANCH=None
BUG=None
TEST=None

Change-Id: Ie87d0ded02849b09d7f8b3c47a574e5f1c90782c
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/282781
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
4 files changed