dmaengine: dw-axi-dmac: 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/dw-axi-dmac/dw-axi-dmac-platform.c:984:34: warning:
        ‘dw_dma_of_id_table’ defined but not used [-Wunused-const-variable=]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201120162303.482126-2-krzk@kernel.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c

@@ -992,7 +992,7 @@ static struct platform_driver dw_driver = {
 	.remove		= dw_remove,
 	.driver = {
 		.name	= KBUILD_MODNAME,
-		.of_match_table = of_match_ptr(dw_dma_of_id_table),
+		.of_match_table = dw_dma_of_id_table,
 		.pm = &dw_axi_dma_pm_ops,
 	},
 };