hw/core: stream: Add an end-of-packet flag

hw/core: stream: Add an end-of-packet flag

Some stream clients stream an endless stream of data while
other clients stream data in packets. Stream interfaces
usually have a way to signal the end of a packet or the
last beat of a transfer.

This adds an end-of-packet flag to the push interface.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-Id: <20200506082513.18751-6-edgar.iglesias@gmail.com>