pinctrl: sh-pfc: Absorb enum IDs in PINMUX_CFG_REG() macro

Currently the PINMUX_CFG_REG() macro must be followed by initialization
data, specifying all enum IDs.  Hence the macro itself does not know
anything about the enum IDs, preventing the macro from performing any
validation on it.

Make the macro accept the enum IDs as a parameter, and update all users.
Note that array data enclosed by curly braces cannot be passed to a
macro as a parameter, hence the enum IDs are wrapped using a new macro
GROUPS().

No functional changes.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>