dmaengine: dw: Remove error message from DT parsing code

Users are a bit frightened of the harmless message that tells that
DT is missed on ACPI-based platforms. Remove it for good, it will
simplify the future conversion to fwnode and device property APIs.

Fixes: a9ddb575d6d6 ("dmaengine: dw_dmac: Enhance device tree support")
Depends-on: f5e84eae7956 ("dmaengine: dw: platform: Split OF helpers to separate module")
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199379
Signed-off-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Serge Semin <[e-mail]>
Tested-by: Serge Semin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/dw/of.c

···
 	u32 nr_masters;
 	u32 nr_channels;
 
-	if (!np) {
-		dev_err(&pdev->dev, "Missing DT data\n");
-		return NULL;
-	}
-
 	if (of_property_read_u32(np, "dma-masters", &nr_masters))
 		return NULL;
 	if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)