Use response pointer and size from host command args struct

Saves 2 params being passed around needlessly.

BUG=chrome-os-partner:11275
TEST=mkbp hash from u-boot console should still work

Change-Id: I958e4a09f16413e4d051e278dc0384aa9b791aa4
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/27312
5 files changed