getmajorbyname() which were a better (sigh) temporary interface to
the going-away devswitches.
Note that SYSINIT()s to initialize the devswitches would be fatal
in syscons.c and pcvt_drv.c (and are bogus elsewhere) because they
get called independently of whether the device is attached; thus
devices that share a major clobber each other's devswitch entries
until the last one wins.
conf.c:
Removed stale #includes and comments.