Attach this driver during BUS_PASS_BUS and move the cpu init code to a
bus_new_pass() handler so it doesn't happen until BUS_PASS_CPU.  This allows
the anatop driver to outbid the generic simplebus driver (which the FDT
data describes as compatible).

Some day when we handle power regulators, this driver may actually
become a functional simplebus and attach the regulators as children, as
described in the FDT data.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273283 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f