regulator: rpi-panel: Add GPIO control for panel and touch resets

regulator: rpi-panel: Add GPIO control for panel and touch resets

We need independent control of the resets for the panel&bridge,
vs the touch controller.

Expose the reset lines that are on the Atmel's port C via the GPIO
API so that they can be controlled appropriately.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Link: https://lore.kernel.org/r/20220124220129.158891-7-detlev.casanova@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>