AVRC_MsgReq() function

* Function AVRC_MsgReq * Description This function is used to send the AVRCP byte stream in p_pkt * down to AVCTP. * It is expected that p_pkt->offset is at least AVCT_MSG_OFFSET * p_pkt->layer_specific is AVCT_DATA_CTRL or AVCT_DATA_BROWSE * p_pkt->event is AVRC_OP_VENDOR, AVRC_OP_PASS_THRU or AVRC_OP_BROWSE * The above BT_HDR settings are set by the AVRC_Bld* functions. * Returns AVRC_SUCCESS if successful. * AVRC_BAD_HANDLE if handle is invalid.