usb: gadget: Update default class subclass and protocol for rndis

This allows Host to load NDIS 6.0 driver for RNDIS over ethernet.
Design objectives of NDIS 6.0 is to enhance driver performance
and scalability. Observing higher peak tput (308Mbps --> 480Mbps)
for FTP transfer on live network. It resolves the data stall that
is being caused by the sudden transfer abort coming from the NDIS
5.0 Host driver.

Change-Id: I503a5573af71eb1b004c68abb64bb04d7e06f9af
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>