picmg: add new keywords
picmg: add new keywords

Get Port State
Port State Should Be
Link Flags Should Be
Link Type Shoould Be
Link Signaling Class Should Be

Signed-off-by: Heiko Thiery <965a85d69f7aa0aa83bbdecf1b37e17133c01ac3@kontron.com>

kontron/robotframework-ipmilibrary