chromeec: Add helper function to read EC switch state

Add a helper function to read the EC switch state on LPC based
ECs instead of having each board need to understand and use the
specific EC LPC IO method that is required.

BUG=chrome-os-partner:43515
BRANCH=none
TEST=build and boot on glados

Original-Change-Id: Id046c7ddf3a1689d4bf2241be5da31184c32c0e1
Original-Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/293514
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>

Change-Id: Id11009e0711b13823e4f76dc9db9c9c20abf4809
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/11280
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2 files changed