[hermon] Reset device during probe()

Some systems will retry their boot sequence in the event of a boot
failure.  On these systems, the second and subsequent boot attempts
will fail to initialise the Hermon HCA.

Fix by resetting the HCA during probe().  This incurs a one-second
cost, but there seems to be no viable alternative.

Originally-fixed-by: Itay Gazit <itaygazit@gmail.com>