dmaengine: mv_xor: drop of_match_ptr from of_device_id table

dmaengine: mv_xor: drop of_match_ptr from of_device_id table

The driver can match only via the DT table so the table should be always
used and the of_match_ptr does not have any sense (this also allows ACPI
matching via PRP0001, even though it is not relevant here).  This fixes
compile warning (!CONFIG_OF on x86_64):

    drivers/dma/mv_xor.c:1281:34: warning:
        ‘mv_xor_dt_ids’ defined but not used [-Wunused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201120162303.482126-3-krzk@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>