sh-pfc: Fix PINMUX_GPIO macro

Commit 7cbb0e55

 ("sh-pfc: Don't duplicate argument to PINMUX_GPIO
macro") erronesouly modified the PINMUX_GPIO macro in a way that
resulted in all pins being named "name". Fix the macro to name the pins
correctly.

Cc: stable@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>