pinctrl: sh-pfc: checker: Move data before code

Restructure the checker to move all data definitions to the top, before
the code.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20200110131927.1029-2-geert+renesas@glider.be