sunxi: Hookup OTG USB controller support

Hookup OTG USB controller support and enable the otg controller + USB-keyb
on various tablets.

This allows tablet owners to interact with u-boot without needing to solder
a serial console onto their tablet PCB.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/arch/arm/include/asm/arch-sunxi/usbc.h b/arch/arm/include/asm/arch-sunxi/usbc.h
index 8d20973..cb538cd 100644
--- a/arch/arm/include/asm/arch-sunxi/usbc.h
+++ b/arch/arm/include/asm/arch-sunxi/usbc.h
@@ -11,6 +11,8 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+extern const struct musb_platform_ops sunxi_musb_ops;
+
 void *sunxi_usbc_get_io_base(int index);
 int sunxi_usbc_request_resources(int index);
 int sunxi_usbc_free_resources(int index);