Use libfdt for is-compatible checks

Testing the 'compatible' property of manifest FDT requires parsing a
list of strings. As this is currently the only use case, we can remove
a significant amount of code from the manifest parser by using a libfdt
API instead.

Change-Id: Idcfa8d9a85745738a08d4fdaa40f30cc18e3c5c2
5 files changed