Add an array property that configures the General Purpose Input (GPI)
register.  The device has 4 GPI pins and each pin can be configured in 1
of 7 different ways.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200526200917.10385-1-dmurphy@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>