gpio: Make "offset" and "unsigned int", not just "unsigned"

gpio: Make "offset" and "unsigned int", not just "unsigned"

When I copied the function prototypes from the GPIO header file into
my own driver, checkpatch yelled at me saying that I shouldn't use use
"unsigned" but instead should say "unsigned int".  Let's make the
header file use "unsigned int" so others who copy like I did won't get
yelled at.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200428172322.2.Iacb3c8152c3cf9015a91308678155a578b0cc050@changeid
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>