media: ov2640: Drop legacy includes

The driver was including legacy headers despite using just
<linux/gpio/consumer.h>. Drop the surplus includes.

Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>