Add get channel payload version command

Implement get channel payload version command (IPMI specification
section 24.9). As per the specification, this command is basically a
hard-coded value that says we are using IPMI 2.0.

Tested:
    ipmitool raw 6 0x4F 3 1 // Command
     10                     // Response

Change-Id: Id16723e7257361814b98f3c14d759f2919ad4c03
Signed-off-by: Ayushi Smriti <smriti.ayushi@intel.com>
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/user_channel/channel_layer.hpp b/user_channel/channel_layer.hpp
index 6dc9fe2..580c4ee 100644
--- a/user_channel/channel_layer.hpp
+++ b/user_channel/channel_layer.hpp
@@ -375,4 +375,12 @@
  */
 uint8_t getChannelByName(const std::string& chName);
 
+/** @brief determines whether payload type is valid
+ *
+ *	@param[in] payload type - Payload Type
+ *
+ *	@return true if valid, false otherwise
+ */
+bool isValidPayloadType(const PayloadType payloadType);
+
 } // namespace ipmi