Introduce PowerPC-specific helper routines for FDT.
Introduce PowerPC-specific helper routines for FDT.

Reviewed by:	imp
Sponsored by:	The FreeBSD Foundation

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase