[devmgr] Add more logging around driver binding

We suspect that something may be causing occasional deadlock around the
time that we attempt to bind the zxcrypt driver.  Add more logging, and
increase verbosity in a couple places to see if we can narrow down where
we're going awry.

DNO-492 #comment
TEST: no behavioral change, just more logging

Change-Id: Ib03af33da1d67533599c80e4453ef27dc160950e