arm: mvebu: Espressobin: Set default value for $ethNaddr env variable

On Espressobin board are MAC addresses stored in U-Boot env area. Therefore
they are not present in default_environment[] array constructed at compile
time.

This change puts permanent MAC addresses into default_environment[] array
at board runtime. Espressobin board has enabled DEFAULT_ENV_IS_RW option
and therefore can modify this array.

This change ensure that 'env default -a' does not delete permanent MAC
addresses from Espressobin env storage area.

Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Andre Heider <a.heider@gmail.com>
diff --git a/include/configs/mvebu_armada-37xx.h b/include/configs/mvebu_armada-37xx.h
index 6df7023..2ad4325 100644
--- a/include/configs/mvebu_armada-37xx.h
+++ b/include/configs/mvebu_armada-37xx.h
@@ -94,6 +94,10 @@
 
 /* filler for default values filled by board_early_init_f() */
 #define ENV_RW_FILLER \
+	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" /* for ethaddr= */ \
+	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" /* for eth1addr= */ \
+	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" /* for eth2addr= */ \
+	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" /* for eth3addr= */ \
 	"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" /* for fdtfile= */ \
 	""