cr50: prepare to release 0.4.9
cr50: prepare to release 0.4.9

BRANCH=cr50, cr50-mp
BUG=none
TEST=none

Change-Id: Ied65e2169a209eaea5d313d6e8461b0f6f219ba2
Signed-off-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1145897
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec