dmaengine: mv_xor: use SoC type instead of directly the operation mode

Currently the main difference between legacy XOR engine and newer one, is
the way the engine modes are setup (either in the descriptor or through
the controller registers). In order to be able to take into account new
generation of the XOR engine for the ARM64 SoC, we need to identify them
by type, and then depending to the type the engine setup will be
selected.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>