pinctrl: sh-pfc: r8a779[01]: Move 'union vin_data' to shared header file

R8A7790/1 PFC  drivers use almost identical  'union vin_data' and completely
identical VIN_DATA_PIN_GROUP() macro; we thus can  move them into the shared
header file...

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>