FireWire upper layer drivers are converted from generic
    struct driver.probe() and .remove()
to bus-specific
    struct fw_driver.probe() and .remove().

The new .probe() adds a const struct ieee1394_device_id *id argument,
indicating the entry in the driver's device identifiers table which
matched the fw_unit to be probed.  This new argument is used by the
snd-firewire-speakers driver to look up device-specific parameters and
methods.  There is at least one other FireWire audio driver currently in
development in which this will be useful too.

The new .remove() drops the unused error return code.

Although all in-tree drivers are being converted to the new methods,
support for the old methods is left in place in this commit.  This
allows public developer trees to merge this commit and then move to the
new fw_driver methods.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Clemens Ladisch <clemens@ladisch.de> (for sound/firewire/)
Cc: Peter Hurley <peter@hurleysoftware.com> (for drivers/staging/fwserial/)