usb: musb: musb_cppi41: Workaround DMA stall issue during teardown

The DMA may hang up if a teardown is initiated while an endpoint is still
active (Advisory 2.3.27 of DA8xx errata).
To workaround this issue, add a delay before to initiate the teardown.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>