pinctrl: sh-pfc: Fix PINMUX_IPSR_PHYS() to set GPSR

This patch allows PINMUX_IPSR_PHYS() to set bits in GPSR.
When assigning function to pin, GPSR should be set to peripheral
function.
For example when using SCL3, GPSR2 bit7 (PWM1_A pin) should be set to
peripheral function.

Signed-off-by: Keiya Nobuta <nobuta.keiya@fujitsu.com>
Link: https://lore.kernel.org/r/20191008060112.29819-1-nobuta.keiya@fujitsu.com
Fixes: 50d1ba17

 ("pinctrl: sh-pfc: Add physical pin multiplexing helper macros")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>