Support broadcast message

1. Support send/recv broadcast message
2. Fix an issue of inconsistent addr between src addr of incoming message
and target addr of response

Tested:
1. CMC broadcast message can be sent and received (BNP)
2. IPMI command injected to i2c bus0 via IPMB header can return correct value (WFP)

Change-Id: Ic03ee4ef6552a40d20594c4abb337f71ae5763eb
Signed-off-by: Qiang XU <qiang.xu@linux.intel.com>
2 files changed