multiple-channel configuration via yaml

Handles converting a yaml file mapping IPMI
channel to ethernet device and using this instead of
a hard-coded map.

Change-Id: Iedfe7cb52a2d0663b9c8a0f6f9d37fe733b63a58
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/types.hpp b/types.hpp
index a43c8c0..62f7db7 100644
--- a/types.hpp
+++ b/types.hpp
@@ -181,6 +181,7 @@
 
 namespace network
 {
+using ChannelEthMap = std::map<int, std::string>;
 
 constexpr auto MAC_ADDRESS_FORMAT = "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx";
 constexpr auto IP_ADDRESS_FORMAT = "%u.%u.%u.%u";