usb: gadget: qti: Add support for MBIM OS descriptor handling

In order to support MBIM for qti gadget in a multi-config usb
composition driver has to support OS descriptor.
This change adds signature field, vendor code, compatibleID and
subCompatibleID in qti gadget and gsi driver for early enumeration
of USB since there is no dependency in userspace.

Change-Id: Ia68ac2d79338fdd6580c7ac906378742d3aaa74e
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>