dpaa2-eth: add a dpaa2_eth_ prefix to all functions in dpaa2-eth-dcb.c

Some static functions in the dpaa2-eth driver don't have the dpaa2_eth_
prefix and this is becoming an inconvenience when looking at, for
example, a perf top output and trying to determine easily which entries
are dpaa2-eth related. Ammend this by adding the prefix to all the
functions.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>