Entertainer Mac Davis, the man behind several of Elvis Presley’s hits including “In The Ghetto,” “A Little Less Conversation,” “Memories” and “Don’t Cry, Daddy,” has died Tuesday at 78.Davis’ manager confirmed the news, according to an announcement by the Country Music Association, adding that the singer had become “critically ill” after undergoing heart surgery in Nashville.Davis, from Lubbock, Texas, who penned a number of songs in the late ’60s and ’70s for the King, went on to top the charts