pinctrl: renesas: r8a779a0: Rename MOD_SEL2_* definitions

Rename the MOD_SEL2_* definitions, to match the bitfield order in
IPxSRy_* definitions and in MOD_SEL* definitions in other drivers.

No changes in generated code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/4880e4cbc112ee26569bf29a21c070125461e58d.1642524603.git.geert+renesas@glider.be