ARM: shmobile: mackerel: Use gpio_request_one()

Replace occurences of gpio_request() and gpio_direction_*() by calls to
gpio_request_one().

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>