usb: dwc2: fix default value for DMA support

The current defaults for DMA results on a non-DMA platform in a unnecessary
error message:

  Invalid value 0 for param gadget-dma

So fix this by using dma_capable as default value.

Fixes: 9962b62f ("usb: dwc2: Deprecate g-use-dma binding")
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/params.c

@@ -1088,7 +1088,7 @@ static void dwc2_set_gadget_dma(struct dwc2_hsotg *hsotg)
 	/* Buffer DMA */
 	dwc2_set_param_bool(hsotg, &p->g_dma,
 			    false, "gadget-dma",
-			    true, false,
+			    dma_capable, false,
 			    dma_capable);
 
 	/* DMA Descriptor */
@@ -1118,7 +1118,7 @@ static void dwc2_set_parameters(struct dwc2_hsotg *hsotg,
 
 		dwc2_set_param_bool(hsotg, &p->host_dma,
 				    false, "host-dma",
-				    true, false,
+				    dma_capable, false,
 				    dma_capable);
 		dwc2_set_param_host_rx_fifo_size(hsotg,
 				params->host_rx_fifo_size);