u-boot-aspeed: Add distro feature for mac2 support

Add a distro feature to enable aspeed nic driver to enable MAC1
and MAC2.

The aspeednic patch is copied from meta-ingrasys/meta-zaius, it is
also required by fp5280g2. To avoid duplication, this distro feature
has been added.

Both meta-fp5280g2 and meta-zaius will be updated to use the distro feature.

Tested: tested on fp5280g2, and both Ethernet ports worked

(From meta-phosphor rev: 5a8e7c5a6efea492b82d710c465125fc9d0afdb9)

Signed-off-by: John Wang <wangzqbj@inspur.com>
Change-Id: Ia754595c5e3762f69397c03021ffe29ea5b9afcc
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/conf/distro/include/phosphor-aspeednic-use-mac2.inc b/meta-phosphor/conf/distro/include/phosphor-aspeednic-use-mac2.inc
new file mode 100644
index 0000000..20fad5b
--- /dev/null
+++ b/meta-phosphor/conf/distro/include/phosphor-aspeednic-use-mac2.inc
@@ -0,0 +1,2 @@
+DISTRO_FEATURES += "obmc-aspeednic-use-mac2"
+DISTROOVERRIDES .= ":df-aspeednic-use-mac2"