- Process some tx done messages in the transmit path, to ensure that
the XLR NA tx done FIFO does not overflow.
- Add a message ring handler API to process atmost a given number of
messages from a specified bucket mask. This will be used to process
the tx done messages
- Add a callout to restart transmit in the case transmit gets blocked.
- Update enable_msgring_int() and disable_msgring_int(), remove unused
args and make static.
Obtained from: Sriram Gorti (srgorti at netlogicmicro dot com)