Add support for LKM operation.
Change M_NOWAIT on buffer memory allocation to M_WAIT in hopes we'll be
able to get ourselves a nice fat buffer from the kernel if we suspend.
Note: The LKM support looks kinda screwy in two areas, where I found
problems with the kernel proper. First, calling dev_attach()
at module load time will cause a panic. I haven't investigated.
Secondly, I had to manually call qcam_drvinit() to register the
device softc structure by hand at module load time. This seems
bogus, it should be called as a core part of the module load
process for character/block device drivers.