Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Change the dev argument from a full path to just the device
identification (e.g. isa:0x3f0 or pci0:2:1:0). In libbus,
the device is turned into a path name. For bus_space_map(),
the resource is now specified in a second argument.
Before:
bus.map('/dev/proto/pci0:2:1:0/pcicfg')
busdma.tag_create('/dev/proto/pci0:2:1:0/busdma', ...)
Now:
bus.map('pci0:2:1:0', 'pcicfg')
busdma.tag_create('pci0:2:1:0', ...)

Rename bus_space to bus (i.e. drop _space). This makes the
API match the convenience macros in <sys/bus.h>. Bus space
can now reference both bus and busdma.