parisc: Improve -fw_cfg opt/OS64 option

Enhance the option to allow user to specify if 32-bit OS,
64-bit OS or both can be installed. The value reflects the
PDC_MODEL_OS32(=2) and PDC_MODEL_OS64(=1) PDC values.
Enhance the boot menu to show currently configured value.

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