configs: Remove CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS in all boards

Now that xHCD does not use CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS,
remove it in all boards' config files.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Tested-by: Stefan Roese <sr@denx.de>
diff --git a/include/configs/mvebu_armada-37xx.h b/include/configs/mvebu_armada-37xx.h
index 778cc9e..feb8112 100644
--- a/include/configs/mvebu_armada-37xx.h
+++ b/include/configs/mvebu_armada-37xx.h
@@ -97,10 +97,8 @@
 #define CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS 3
 
 /* USB 3.0 */
-#define CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS 3
-
 #define CONFIG_USB_MAX_CONTROLLER_COUNT (CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS + \
-					 CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS)
+					 3)
 
 /* USB ethernet */
 #define CONFIG_USB_HOST_ETHER