mec1322: gpio: Properly set alternate GPIO function
mec1322: gpio: Properly set alternate GPIO function

func < 0 should assign the pin as a GPIO.

BUG=chrome-os-partner:39400
TEST=None
BRANCH=None

Signed-off-by: Shawn Nematbakhsh <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>
Change-Id: I231c65a9d660127caf06ff8b235f26563926804d
Reviewed-on: https://chromium-review.googlesource.com/266779
Reviewed-by: Alec Berg <1a4429eeda29095a12e19a73405f80f5b7f37a63@chromium.org>

coreboot/chrome-ec,fourier49/BIZ_EC,fourier49/BZ_DEV_EC,fourier49/BIZ_EC,md5555/ec,fourier49/BZ_DEV_EC,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,md5555/ec,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,akappy7/ChromeOS_EC_LED_Diagnostics,md5555/ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,md5555/ec,coreboot/chrome-ec,fourier49/BIZ_EC,fourier49/BIZ_EC,akappy7/ChromeOS_EC_LED_Diagnostics,fourier49/BZ_DEV_EC,fourier49/BZ_DEV_EC