usb:hsotg:samsung: NAK management for EP0 (Setup stage of control transfers)

For SETUP stage of USB control transmission, the NAK shall NOT be
CLEAR.

The SNAK/CNAK control is crucial for this type of driver,
since data arrives to earlier defined requests.

Tested with:
- DFU gadget (various size of the sent data - also packet = MPS)
- Ethernet gadget (CDC and RNDIS)
- Multi Function Gadget (g_multi)

HW:
- Samsung's C210 Universal rev.0

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>