pinctrl: renesas: r8a7740: Share BSC pin group data

Pin groups bsc_data{8,16} are subsets of bsc_data32.
Pin groups bsc_rd_we{8,16} are subsets of bsc_rd_we32.

This reduces kernel size by 232 bytes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/556873f8392b1a7d1a2cf9c10abb5e6c283f11cc.1640269757.git.geert+renesas@glider.be