Morgan Stanley is calling for significant upside in Arm Holdings stock.Semiconductor stocks are among the hottest choices for artificial intelligence (AI) investors right now. While companies such as Nvidia, AMD, and Broadcom often garner outsize attention in the chip space, smart investors realize that there are other opportunities that present potentially lucrative returns over the long run.Recently, Lee Simpson of Morgan Stanley upgraded his price target for Arm Holdings (ARM -6.63%) to $190 -- implying ...