kirby: Enable the internal pull up on the recovery mode pin.

The recovery mode pin has no external pull up and will float low, turning on
recovery mode even though nobody asked for it. We should enable the internal
pull up so that it doesn't float around.

BUG=None
TEST=Built and booted into depthcharge on kirby. Saw that a manual recovery
mode request was no longer detected. Now we end up in recovery mode because
we have no disk.
BRANCH=None

Change-Id: Ic9c5d7ea4b584e770030cdf5dbb1fa37f0344db8
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://gerrit.chromium.org/gerrit/66880
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
1 file changed