chip-independent clock code. 'clock' has been renamed 'mcclock' 'clock'
has been renamed 'mcclock' (since it's a driver for that particular
clock, and since eventually there may be another clock chip driver),
and now attaches via seperate match/attach functions to both TC and ISA.
This removes a whole lot of #ifdefs...
- split softc size and match/attach out from cfdriver into
a new struct cfattach.
- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.
Support for AXPpci CPUs,
Support for AlphaStation 600 CPUs,
new boot block structure, which requires an 'installboot'
program and works a lot like the NetBSD/sparc boot blocks.
