media: staging: media: starfive: camss: Add core driver

Add core driver for StarFive Camera Subsystem. The code parses
the device platform resources and registers related devices.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>