pinctrl: renesas: r8a77990: Share QSPI pin group data

Pin groups qspi[01]_data2 are subsets of qspi[01]_data4.

This reduces kernel size by 32 bytes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/54779df96c1e0fc9ce02786cfd9f66d4cfc063f0.1640269757.git.geert+renesas@glider.be