media: ipu-bridge: Add a ipu_bridge_parse_ssdb() helper function

The code to go from ACPI sensor info to a fwnode-tree with connector
nodes and endpoint properties is 99% the same for the atomisp2 and
the IPU3.

The main difference is that atomisp2 devices do not have a SSDB table
with various info.

Abstract out the parsing of the sensor's ACPI fwnode into a helper
function and store the parsed results, rather then the raw SSDB
in struct ipu_sensor.

This is a preparation patch for making the ipu-bridge code more generic
so that it can be shared with the atomisp driver.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>