doc: Add dt-bindings and descriptions for ADI SC5xx-family pinctrl

This adds the necessary dt-bindings and documentation to use the ADI
SC5xx pinctrl driver in a device tree. It is not yet available upstream
in the Linux kernel. Eventually, it will be moved there.

Signed-off-by: Vasileios Bimpikas <vasileios.bimpikas@analog.com>
Signed-off-by: Utsav Agarwal <utsav.agarwal@analog.com>
Signed-off-by: Arturs Artamonovs <arturs.artamonovs@analog.com>
Signed-off-by: Greg Malysa <malysagreg@gmail.com>
3 files changed