At present GPIOs must be staticly defined in a table. This is efficient
but inflexible, and requires error-prone and correponding #ifdefs both
in the board's gpio.h and gpio.c files.
Create a GPIO_UNSET option for GPIOs. This allows them to be assigned
an enum value, but have the actual use under program control.
BUG=chrome-os-partner:13064
BRANCH=snow,link
TEST=manual
build and boot on snow with later changes. See the AC power GPIO does
not change when un/plugging power.
Change-Id: Iab58275923d7d6cfce62c890b5db9b6758279a4c
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/31302
Reviewed-by: David Hendricks <dhendrix@chromium.org>