usb: gadget: u_ctrl_hsic: Fix hsic control endpoint stall

The USB EHCI and XHCI drivers assume that there will be only IN
status stage for 0 data length control transfers. If the device
connected over HSIC submits data on the control OUT endpoint, the
control transfer will never get finished.

There is no significance to 0 length SEND_ENCAPSULATED command. Fix
the control endpoint stall by dropping such packets.

CRs-Fixed: 563403
Change-Id: Ia9d4d8f6437abde7faffabbe5105cd53b9f2cd4d
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>