Add call to bus_generic_attach() at the end of sk_attach(). It turns out that

Add call to bus_generic_attach() at the end of sk_attach(). It turns out that
if you kldload this driver, all the subordinate devices are probed/attached
as expected. But this is not the case when the driver is statically compiled
into the kernel. Since I do most of my testing with modules, I failed to
notice this. I'm not sure if it's intended behavior or not. I think it may
be, but it seems a little counter-intuitive.