Input: exc3000 - add reset gpio support

Add basic support for an optional reset gpio.

Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200805160520.456570-4-sebastian.reichel@collabora.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>