As PFC registers are either 8, 16, or 32 bits wide, use u32 (mostly
replacing unsigned long) to store (parts of) register values and masks.

Switch the shadow register operations from {set,clear}_bit() to plain C
bit operations, as the former can operate on long data only.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>