usb: dwc2: Make the DMA descriptor structure packed

Make the DMA descriptor structure packed to guarantee alignment and size
in memory.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/hw.h

@@ -802,7 +802,7 @@
 struct dwc2_dma_desc {
 	u32 status;
 	u32 buf;
-};
+} __packed;
 
 #define HOST_DMA_A			(1 << 31)
 #define HOST_DMA_STS_MASK		(0x3 << 28)