Add a function to translate device_state enum into a string, then use
it for printing the ec and RDD state.
Refactor ec_state so that all state transitions go through a
set_state() function, which makes it easier to turn on debugging all
state transitions. That's normally not compiled in because it would
be spammy during debouncing.
BUG=none
BRANCH=cr50
TEST=ccd command prints EC and RDD states
Change-Id: Ie7bc56c7b66beee23d1d1989711c640e5e39ce43
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/642121
Reviewed-by: Mary Ruthven <mruthven@chromium.org>