usb: gadget: udc: atmel: Fix interrupt storm in FIFO mode.

[ Upstream commit ba3a1a915c49cc3023e4ddfc88f21e7514e82aa4 ]

Fix interrupt storm generated by endpoints when working in FIFO mode.
The TX_COMPLETE interrupt is used only by control endpoints processing.
Do not enable it for other types of endpoints.

Fixes: 914a3f3b ("USB: add atmel_usba_udc driver")
Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>