HID: mcp2221: correct undefined references when CONFIG_GPIOLIB isn't defined

Singular #ifdef IS_REACHABLE(CONFIG_GPIOLIB) weren't covering all the
gpiolib functions that were being referenced.

Update the code regions that are commented out when CONFIG_GPIOLIB isn't
enabled to avoid errors.

Fixes: 960f9df7

 ("HID: mcp2221: add ADC/DAC support via iio subsystem")
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>