RMCP+ login support with privilege

Implementation of RMCP login support with appropriate
privilege level.

Unit Test:
1. Verified that user is able to login without any issues
2. Privilege of the user is minimum of requested, user & channel
3. Unable to set higher privilege using Set session commands

Change-Id: I5e9ef21dfc1f1b50aa815562a3a65d90c434877c
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>
6 files changed