Add send message functions and receive dispatch stubs
for power gating isolation hbm protocol.

The protocol consist of requests for entering and exiting
the power gating isolation state and their responses.
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>