usb: gadget: add super speed support

This patch is to add usb gadget super speed support in common
driver, including BOS descriptor and select the super speed
descriptor from function driver.

Reviewed-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Tested-by: faqiang.zhu <faqiang.zhu@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>