pinctrl: renesas: core: Drop unneeded #ifdef CONFIG_OF

As the of_node member of struct device always exists, and there is a
dummy of of_device_get_match_data() for the !CONFIG_OF case, there is no
longer a need to protect code using these interfaces with an #ifdef.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/55d72ce46b43ec2f41681cb5ba7ca7fcebdb98d1.1679416005.git.geert+renesas@glider.be