parisc: Add constants for PDC_RELOCATE PDC call

The PDC_RELOCATE function is called by HP-UX shortly before crashing.
So, we need to handle it in qemu and thus it makes sense to add the
constant here.

Additionally add other subfunctions like PDC_MODEL_GET_PLATFORM_INFO (to
get product and serial numbers) and PDC_TOD_CALIBRATE (to calibrate
timers) too.

Signed-off-by: Helge Deller <deller@gmx.de>