pinctrl: renesas: Rename SH_PFC_PIN_GROUP{,_ALIAS} args

Rename the arguments of the SH_PFC_PIN_GROUP_ALIAS() and
SH_PFC_PIN_GROUP() macros, to better reflect their purposes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/495fd5cd910d59489f4c1336e4a02da3679b5ffb.1640269757.git.geert+renesas@glider.be