Add COP2 support for direct drive networks

The NPU driver now supports parsing and validating the custom operator
payload 2 (COP2) in the network data for direct drive.

Change-Id: Iafc99f4461b7cc9905c50ab44bf23ec88a4a1e3e
Signed-off-by: Mikael Olsson <mikael.olsson@arm.com>