usb: musb: jz4740: Add support for DMA

Add support for using the DMA channels built into the Inventra IP.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Artur Rojek <contact@artur-rojek.eu>
Signed-off-by: Bin Liu <b-liu@ti.com>
Link: https://lore.kernel.org/r/20200316211136.2274-4-b-liu@ti.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>