pinctrl: renesas: checker: Restrict checks to Renesas platforms

When DEBUG is defined (e.g. if CONFIG_DEBUG_PINCTRL=y), the Renesas pin
control driver runs sanity checks against the pin control tables.  This
may cause lots of output on the console, and can be annoying in ARM
multi-platform kernels.  Fix this by only running the checks when
running on SuperH, or on a DT platform supported by the Renesas pin
controller driver.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210111165013.496897-1-geert+renesas@glider.be