crossystem: support recoverysw_cur with new gpiod API

We've dropped the chromeos_arm driver on recent kernels. Now, if you
name the GPIO as RECOVERY_SW_L (e.g., in the Device Tree), crossystem
can pick it up directly.

BRANCH=none
BUG=chromium:897992, b:116761006
TEST=crossystem recoverysw_cur on ARM with 4.14+ (without chromeos_arm
     driver)

Change-Id: I20fb1aa310268a60070bd6c8914c4d58e5760cf8
Reviewed-on: https://chromium-review.googlesource.com/1448395
Commit-Ready: Brian Norris <briannorris@chromium.org>
Tested-by: SANTHOSH JANARDHANA HASSAN <sahassan@google.com>
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
1 file changed