pinctrl: sh-pfc: r8a77995: Remove bogus SEL_PWM[0-3]_3 configurations

While the SEL_PWM[0-3] fields in the Module Select Register 0 support 4
possible configurations per PWM pin, only the first 3 are valid.

Replace the invalid and unused configurations for SEL_PWM[0-3]_3 by
dummies.

Fixes: 794a6711 ("pinctrl: sh-pfc: Initial R8A77995 PFC support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>