usb: composite: add BOS descriptor support to composite framework

To add usb-3.0 support to peripheral device add BOS & SS capability
descriptors to gadget composite framework.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>