media: si4713: Use the right include

The driver includes the legacy <linux/gpio.h> header but uses
<linux/gpio/consumer.h>.

Cc: Dinesh Ram <Dinesh.Ram@cern.ch>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>