Nvidia shares have more room to run — even after notching all-time highs this year, according to Citi. Analyst Atif Malik raised his price target by $100 to $520 while maintaining his buy rating. Malik's target implies an upside of 14.4% over the next year. That means Malik sees more steam in Nvidia's rally. The stock has skyrocketed more than 200% to all-time highs since the start if the year as investors have grown increasingly excited about the potential for artificial intelligence. NVDA YTD mountain Nvidia's strong year Malik's bull case implies the rally could go even further to $600…