usb: dwc3: allocate setup_buf with dma_alloc_coherent()

Since setup_buf is also consumed by hardware DMA, aligns it's
allocation like other hardware buffers by introduce setup_buf_addr
populated by dma_alloc_coherent(), and use it to pass the physical
address of the buffer to the hardware.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20241011-u-boot-dwc3-gadget-dcache-fixup-v4-1-5f3498d8035b@linaro.org
Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 7374ce9..b572ea3 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -670,6 +670,7 @@
  * @ep0_trb: dma address of ep0_trb
  * @ep0_usb_req: dummy req used while handling STD USB requests
  * @ep0_bounce_addr: dma address of ep0_bounce
+ * @setup_buf_addr: dma address of setup_buf
  * @scratch_addr: dma address of scratchbuf
  * @lock: for synchronizing
  * @dev: pointer to our struct device
@@ -757,6 +758,7 @@
 	dma_addr_t		ep0_trb_addr;
 	dma_addr_t		ep0_bounce_addr;
 	dma_addr_t		scratch_addr;
+	dma_addr_t		setup_buf_addr;
 	struct dwc3_request	ep0_usb_req;
 
 	/* device lock */