pinctrl: renesas: rza1: Fix kerneldoc function names

make W=1:

    drivers/pinctrl/renesas/pinctrl-rza1.c:770: warning: expecting prototype for rza1_gpio_disable_free(). Prototype was for rza1_gpio_free() instead
    drivers/pinctrl/renesas/pinctrl-rza1.c:889: warning: expecting prototype for rza1_parse_pmx_function(). Prototype was for rza1_parse_pinmux_node() instead

Fixes: 5a49b644 ("pinctrl: Renesas RZ/A1 pin and gpio controller")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Link: https://lore.kernel.org/r/2188ede78110c64b8a3bfbfa794a085dac0e4cd2.1634645735.git.geert+renesas@glider.be