usb: musb: host: support DMA transfers greater than max channel length

Add support for MUSB Host DMA transfers greater than max
channel length, so that such transfers won't be truncated.

Signed-off-by: Anil Shetty <anil@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>