parisc: SEABIOS_HPPA_VERSION 8

Fixes
- boot of HP-UX with SMP, and
- reboot of Linux and HP-UX with SMP

Enhancements:
- show qemu version in boot menu
- adds exit menu entry in boot menu to quit emulation
- allow to trace PCD_CHASSIS codes more specifically

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