Removed suspect FPA probing code, instead use the ARM FPE to probe the FPA.
Neatened up the FPE attachment code.
Recognise StrongARM class of cpu.
Updated the fpa instruction bounce handler to expect a 4th argument
when called on an undefined trap to match recent changes made to
undefined handlers.
- 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.