usb: gadget: composite: Report various SSP sublink speeds

If a gadget supports SuperSpeed Plus, then it may operate in different
sublink speeds. For example, if the gadget supports SuperSpeed Plus
gen2x2, then it can support 2 sublink speeds gen1 and gen2. Inform the
host of these speeds in the BOS descriptor.

Use 1 SSID if the gadget supports up to gen2x1, or not specified:
- SSID 0 for symmetric RX/TX sublink speed of 10 Gbps.

Use 1 SSID if the gadget supports up to gen1x2:
- SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.

Use 2 SSIDs if the gadget supports up to gen2x2:
- SSID 0 for symmetric RX/TX sublink speed of 5 Gbps.
- SSID 1 for symmetric RX/TX sublink speed of 10 Gbps.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/eb0386fdd5d87a858281e8006a72723d3732240f.1610592135.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>