olimex_a20_olinuxino_micro: initialize the network with DHCP

To allow a more complete "out-of-the-box" startup with the defconfig,
enable automatic network configuration of eth0 using DHCP.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

configs/olimex_a20_olinuxino_micro_defconfig

@@ -12,6 +12,7 @@ BR2_TARGET_GENERIC_HOSTNAME="a20-olinuxino"
 BR2_TARGET_GENERIC_ISSUE="Welcome to OLinuXino!"
 BR2_TARGET_GENERIC_GETTY=y
 BR2_TARGET_GENERIC_GETTY_PORT="ttyS0"
+BR2_SYSTEM_DHCP="eth0"
 BR2_ROOTFS_POST_BUILD_SCRIPT="board/olimex/a20_olinuxino/post-build.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="board/olimex/a20_olinuxino/boot.cmd $(TARGET_DIR)/boot"