Add an all purpose, single byte management TLV.

Many of the single field management messages have just two bytes, one for
the data value and one for padding. This patch adds a structure that can
be used for all of these management IDs.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

tlv.h

@@ -114,6 +114,11 @@ struct management_tlv {
 	Octet         data[0];
 } PACKED;
 
+struct management_tlv_datum {
+	uint8_t val;
+	uint8_t reserved;
+} PACKED;
+
 struct management_error_status {
 	Enumeration16 type;
 	UInteger16    length;