IPMB transfer function shall be refactored

[BonnieLo]

Owner:
Wiwynn

Request from:
#195

Description:
The function IPMB_TXTask() should be broken out as it is over 300 lines long and tries to handle all
interfaces. It would be better to create separate functions for each interface and not have it as
a large if/else-if/else-if/else type structure.