base-files: create /etc/ethers by default

/etc/ethers is missing on /rom but always created when dnsmasq
runs. It is better to have it in place and avoid an extra change
in flash after firstboot.

It will generate an extra /etc/ethers-opkg when it has changed.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
(backported from d810d44e5a)

package/base-files/Makefile

@@ -49,6 +49,7 @@ define Package/base-files/conffiles
 /etc/config/system
 /etc/crontabs/
 /etc/dropbear/
+/etc/ethers
 /etc/group
 /etc/hosts
 /etc/inittab

package/base-files/files/etc/ethers

@@ -0,0 +1,6 @@
+#
+#  Lookup man 5 ethers for syntax documentation
+#
+#  Examples :
+#	02:00:11:22:33:44	OpenWrt.lan
+#	02:00:11:22:33:44	192.168.1.1