media: ov5675: add device-tree support and support runtime PM

Until now, this driver only supported ACPI. This adds support for
Device Tree too while enabling clock and regulators in runtime PM.

Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>