- drop support for PP500x: it's very different from other PP and although
it would be possible to support them, I don't have one to test the code
- make sure only the CPU is started
- add PP descriptor to report chip ID and revision
- add code in shell and lua to support pp (no register description yet)
- compile for ARMv4 because PP502x is an ARM7TDMI
Change-Id: I36c4e465dfc2cfdfe7433b2f65cc8f6f0720fe62
