pinctrl: renesas: Remove unneeded #include <linux/init.h>

The last __init annotations were removed from these source files almost
one decade ago.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/fb71c409ea3ad76163496e305dc955ca8e84416d.1649681741.git.geert+renesas@glider.be