uboot-imx

usb: musb: Remove legacy CONFIG_USB_DA8XX

There don't appear to be any boards enabling CONFIG_USB_DA8XX,
and there is a newer version of the MUSB driver, so let's remove
the legacy version of it.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Jean-Jacques Hiblot <jjhiblot@ti.com>