pinctrl: renesas: r8a7740: Share LCD pin group data

Pin groups lcd0_data{8,9,12,16,18} are subsets of lcd0_data24_0.
Pin groups lcd1_data{8,9,12,16,18} are subsets of lcd1_data24.

This reduces kernel size by 1008 bytes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2018113779b3084c4175b04bb32acf2de0557a37.1640269757.git.geert+renesas@glider.be