usb: musb: enable ux500 host side dma support

Host side dma support for ux500 is enabled by piggybacking on Inventra
dma support.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>