USB: rmnet: Add support for new composition framework

Following command need to be issued to select the number
of RMNET instances (once only):
-->echo 1 > /sys/class/android_usb/android0/f_rmnet/instances

Signed-off-by: Manu Gautam <mgautam@codeaurora.org>

Conflicts:

	drivers/usb/gadget/u_rmnet_ctrl_smd.c
3 files changed