gpio_request_one() and gpio_request_array() make use of
gpio_direction_*, so it is natural to define the former them further low
in the file. It doesn't matter for the compiler here as all functions
are declared in a header, but the next commit adds a few more functions
and it benefits from this reordering by not needing forward
declarations.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>