media: i2c: rj54n1: Remove soc_camera dependencies

Remove soc_camera framework dependencies from rj54n1 sensor driver.
- Handle clock
- Handle GPIOs (named 'powerup' and 'enable')
- Register the async subdevice
- Remove g/s_mbus_config as they're deprecated.
- Adjust build system
- List the driver as maintained for 'Odd Fixes' as I don't have HW to test.

This commits does not remove the original soc_camera based driver.

Compiled tested only.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>