usb: chipidea: udc: only clear active and halted bits in qhead

The datasheet of the synopsys core describes only to overwrite the
active and halted bits in the qhead before priming any endpoint.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Reviewed-by: Felipe Balbi <balbi@ti.com>
[Alex: fixed a case of line-too-long]
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>