usb: dwc3: omap: drop dma_mask configuration

The DWC3 OMAP driver supports DT-boot only, as result dma_mask will be
always configured properly from DT -
of_platform_device_create_pdata()->of_dma_configure(). More over,
dwc3-omap.c can be built as module and in this case it's unsafe to
assign local variable as dma_mask.

Hence, remove dma_mask configuration code.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/dwc3-omap.c

@@ -331,8 +331,6 @@ static void dwc3_omap_disable_irqs(struct dwc3_omap *omap)
 	dwc3_omap_write_irqmisc_clr(omap, reg);
 }
 
-static u64 dwc3_omap_dma_mask = DMA_BIT_MASK(32);
-
 static int dwc3_omap_id_notifier(struct notifier_block *nb,
 	unsigned long event, void *ptr)
 {
@@ -490,7 +488,6 @@ static int dwc3_omap_probe(struct platform_device *pdev)
 	omap->irq	= irq;
 	omap->base	= base;
 	omap->vbus_reg	= vbus_reg;
-	dev->dma_mask	= &dwc3_omap_dma_mask;
 
 	pm_runtime_enable(dev);
 	ret = pm_runtime_get_sync(dev);