USB: composite: Send stall when no config is active

Whenever composition switch happens, android driver stops data transfers &
removes configuation before disabling pullup. Due to this, there is small
window during which pullup is active and device ends up sending device
descriptor with zero confiurations in certain scenarios of Host PC reboot.
Hence fix the issue by stalling control endpoint in this scenario.

Change-Id: I3d3c0321d9311617c6ee492c55809f36de6ae412
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>