dmaengine: idxd: move probe() bits for idxd 'struct device' to device.c

Move the code related to a ->probe() function for the idxd
'struct device' to device.c to prep for the idxd device
sub-driver in device.c.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/162637464189.744545.17423830646786162194.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>