Add suppport for retrieving machine name

This adds support for reading /etc/os-release, parsing out
OPENBMC_TARGET_MACHINE and returning this to the caller.

Change-Id: If2a419b9a77597686f5137efce97b1150142f181
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/handler.hpp b/handler.hpp
index 19fd1ea..766ddde 100644
--- a/handler.hpp
+++ b/handler.hpp
@@ -67,6 +67,14 @@
                                       std::uint8_t instance) = 0;
 
     /**
+     * Return the name of the machine, parsed from release information.
+     *
+     * @return the machine name
+     * @throw IpmiException on failure.
+     */
+    virtual std::string getMachineName() = 0;
+
+    /**
      * Populate the i2c-pcie mapping vector.
      */
     virtual void buildI2cPcieMapping() = 0;