dmaengine: idxd: reflect shadow copy of traffic class programming

The traffic class are set to -1 at initialization until the user programs
them. If the user choose not to, the driver will program appropriate
defaults. The driver also needs to update the shadowed copies of the values
after doing the programming.

Fixes: c52ca478

 ("dmaengine: idxd: add configuration component of driver")
Reported-by: Yixin Zhang <yixin.zhang@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/158386263076.10898.4586509576813094559.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>