pinctrl: renesas: sh73a0: Share LCD pin group data

Pin groups lcd{,2}_data{8,9,12,16,18} are subsets of lcd{,2}_data24.

This reduces kernel size by 1008 bytes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/32561ca31b590424f494351a737473200102bf8c.1640269757.git.geert+renesas@glider.be