* July U.S (Other OTC: UBGXF - news) . producer prices rise; industrial output up * King Digital, El Pollo Loco (NasdaqGS: LOCO - news) slump as results disappoint * J.C. Penney, Nordstrom (NYSE: JWN - news) rise after strong results * Indexes up: Dow 0.2 pct, S&P 0.1 pct, Nasdaq 0.03 pct (Updates to open) Aug 14 (Reuters) - Wall Street was slightly higher on Friday as a raft of positive data pointed to a bullish signal for third-quarter economic growth. The Dow and the S&P 500 were on track to post slight gains for the week, but the Nasdaq was poised to close flat in a choppy week that saw China devalue its currency, hitting markets and derailing predictions of a rate hike. U.S. producer prices rose for a third straight month in July, suggesting the drag on inflation from weaker oil prices was easing, while industrial output advanced at its... More