usb: gadget: composite: Send BOS descriptor if L1 is enabled

Send BOS descriptor to host when L1 is enabled via enable_l1_for_hs
module param. This is needed to pass USBCV Ch9 tests.

Change-Id: I924bccfc25dba4a10d19a6301f425f53fa46f508
Signed-off-by: Devdutt Patnaik <dpatnaik@codeaurora.org>