can: rcar_canfd: Update RCANFD_GAFLCFG macro

Update RCANFD_GAFLCFG macro by replacing the parameter ch->w, where w is
the GAFLCFG index used in the hardware manual.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://patch.msgid.link/20250417054320.14100-9-biju.das.jz@bp.renesas.com


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>