mv_feroceon: default eth and pon mac address envs to sysvar equivalents.

The eth and pon mac addresses are passed to Linux via a Marvell ARM tag. The
value of those tags comes from the eth and pon mac address environment
variables.

This change seeds those envs with the corresponding sysvars ETH_MAC_ADDR and
PON_MAC_ADDR (if they exist).

Change-Id: I2e4b4a158f37d127ff51f0355c161edcab31612a
1 file changed