pinctrl: sh-pfc: pfc-r8a7790: Add VIN2 and VIN3 pins

There are VIN2 and VIN3 channels available on the R8A7790 SoC.
VIN2 supports 4/8/16/18/24-bit data, while VIN3 supports 8-bit.
Add both here, covering all possible data pin configurations.

Signed-off-by: Valentine Barshak <valentine.barshak@cogentembedded.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>