[OpenBIOS] OpenBIOS PowerPC missing open firmware commands

[Alexander von Gluck]

Just a few things I noticed while hacking away at Haiku on PowerPC:

The following OpenFirmware commands aren't implemented:

erase-screen
toggle-cursor

The following paths are missing essential information:

cpu node -> clock-frequency
cpu node -> timebase-frequency
cpu node -> bus-frequency

Example:

cd /
cd cpus
cd PowerPC,750@0
.properties

These properties are present on real PowerPC hardware, but are set to 0 
(or missing in the case of bus-frequency) on the qemu OpenBIOS.

Thoughts?

Thanks!
  -- Alex