sh-pfc: Compute pin ranges automatically

Remove the manually specified ranges from PFC SoC data and compute the
ranges automatically. This prevents ranges from being out-of-sync with
pins definitions.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Yusuke Goda <yusuke.goda.sx@renesas.com>