dmaengine: idxd: add missing dsa driver unregister

dmaengine: idxd: add missing dsa driver unregister

[ Upstream commit 077cdb355b3d8ee0f258856962e6dac06e744401 ]

The idxd_unregister_driver() has never been called for the idxd driver upon
removal. Add fix to call unregister driver on module removal.

Fixes: c52ca478233c ("dmaengine: idxd: add configuration component of driver")
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161947994449.1053102.13189942817915448216.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>