On modern Renesas SoCs, all PFC registers are 32-bit, and all callers of
sh_pfc_{read,write}_reg() already operate on 32-bit registers only.
Hence make the 32-bit width implicit, and rename the functions to
sh_pfc_{read,write}() to shorten lines.

All accesses to 8-bit or 16-bit registers are still done using
sh_pfc_{read,write}_raw_reg().
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>