dmaengine: IOATDMA: revise channel reset workaround on CB3.3 platforms

Previously we unloaded the interrupts and reloaded in order to work around
a channel reset bug that cleared the MSIX table. This approach just isn't
practical when a reset needs to happen in the error handler that just
happens to be running in interrupt context (bottom half). It looks like we
can work around the hardware issue by just storing a shadow copy of the
MSIX table and restore it after reset.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>