Merge 08105d29 on remote branch

/* base message ID header */

typedef PREPACK struct {

    A_UINT32 MessageID: 16,

             reserved : 16;

             MetaData:   8,

             reserved:   8;

} POSTPACK HTC_UNKNOWN_MSG;

#define HTC_UNKNOWN_MSG_MESSAGEID_LSB                 0

#define HTC_UNKNOWN_MSG_MESSAGEID_MASK                0x0000ffff

#define HTC_UNKNOWN_MSG_MESSAGEID_OFFSET              0x00000000

#define HTC_UNKNOWN_MSG_METADATA_LSB                  16

#define HTC_UNKNOWN_MSG_METADATA_MASK                 0X00ff0000

#define HTC_UNKNOWN_MSG_METADATA_OFFSET               0x00000000

/* HTC ready message

 * direction : target-to-host  */