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: I062d07ff3bd63b8a610166cf77714424055d962c
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>