The veteran telecom is on an upswing from a multiyear turnaround.What a difference a year makes for telecom giant AT&T (T -0.27%). Its stock price rose in recent months, reaching a 52-week high of $19.32 on July 1.The stock's surge is a reversal from last July's 52-week low of$13.43. Part of the credit for the share price gains is due to analyst upgrades. JPMorgan, Goldman Sachs, and Barclays were among those upgrading AT&T stock this year.Does this suggest now is the time to pick up shares? To answer that ...