rpmsg: fix build warning when dma_addr_t is 64-bit

dev_dbg() in rpmsg_probe() made use of the %x formatting that
expects an 'unsigned int' which dma_addr_t is not in cases where
dma_addr_t is 64-bit (CONFIG_ARCH_DMA_ADDR_T_64BIT). Casting to
a 'unsigned long long' and using %llx will avoid this.
Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
CC: Ohad Ben-Cohen <ohad@wizery.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>

drivers/rpmsg/virtio_rpmsg_bus.c

@@ -916,8 +916,8 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	if (!bufs_va)
 		goto vqs_del;
 
-	dev_dbg(&vdev->dev, "buffers: va %p, dma 0x%x\n", bufs_va,
-						vrp->bufs_dma);
+	dev_dbg(&vdev->dev, "buffers: va %p, dma 0x%llx\n", bufs_va,
+					(unsigned long long)vrp->bufs_dma);
 
 	/* half of the buffers is dedicated for RX */
 	vrp->rbufs = bufs_va;