Issue #666, Change message definitions to ensure alignment

Update the CFE_ES_ShellTlm_t, CFE_TIME_ToneSignalCmd_t, and
CFE_TIME_FakeToneCmd_t to use the CFE_SB_TlmHdr_t/CFE_SB_CmdHdr_t
types to define the buffer, rather than a uint8 array.

This should not change the size, as it was already defined using
sizeof() this structure, but it will make it aligned correctly
which resolves the compiler warning.

Note that all CMD/TLM should really be defined this way, but
this only selectively changes the places that were actually
generating a compiler warning about this.  There is a risk
that padding will be added, but this change should not change
the padding or size of messages in 32-bit builds.

fsw/cfe-core/src/inc/cfe_es_msg.h

@@ -1601,7 +1601,7 @@ typedef struct
  */
 typedef struct
 {
-    uint8                           TlmHeader[CFE_SB_TLM_HDR_SIZE]; /**< \brief cFE Software Bus Telemetry Message Header */
+    CFE_SB_TlmHdr_t                 TlmHeader; /**< \brief cFE Software Bus Telemetry Message Header */
     CFE_ES_ShellPacket_Payload_t    Payload;
 }CFE_ES_ShellTlm_t;
 #endif /* CFE_OMIT_DEPRECATED_6_7 */

fsw/cfe-core/src/inc/cfe_time_msg.h

@@ -878,7 +878,7 @@ typedef struct
 */
 typedef struct
 {
-  uint8                 CmdHeader[CFE_SB_CMD_HDR_SIZE];
+  CFE_SB_CmdHdr_t         CmdHeader;
 
 } CFE_TIME_ToneSignalCmd_t;
 
@@ -888,7 +888,7 @@ typedef struct
 */
 typedef struct
 {
-  uint8                 CmdHeader[CFE_SB_CMD_HDR_SIZE];
+    CFE_SB_CmdHdr_t       CmdHeader;
 
 } CFE_TIME_FakeToneCmd_t;
 

fsw/cfe-core/src/time/cfe_time_utils.h

@@ -277,7 +277,7 @@ typedef struct
   /*
   ** Local 1Hz wake-up command packet (not related to time at tone)...
   */
-  CCSDS_CommandPacket_t Local1HzCmd;
+  CFE_SB_CmdHdr_t Local1HzCmd;
 
   /*
   ** Time at the tone command packets (sent by time servers)...
@@ -294,7 +294,7 @@ typedef struct
    * "tone signal" message above.
    */
 #if (CFE_MISSION_TIME_CFG_FAKE_TONE == true)
-  CCSDS_CommandPacket_t  ToneSendCmd;
+  CFE_SB_CmdHdr_t  ToneSendCmd;
 #endif
 
   /*