IPMI channel support test use case

Added:
   - Test case to verify supported IPMI channel of the system.
   - Test case to verify invalid IPMI channel response.
   - Keyword to get the MAC address.
   - Keyword to get the valid physical network count.
   - Added expect_error parameter to standard IPMI keyword args.

For reference: openbmc/openbmc#3036

Resolves  openbmc/openbmc-test-automation#1313

Change-Id: Ie94e87094056248c335822b1bdc41b8254bfa343
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
3 files changed