KANSAS CITY, Mo. — The first drive in Baltimore covered 81 yards in 10 plays, so by the time quarterback Patrick Mahomes arrived to the Chiefs’ sideline after KC’s opening-possession touchdown, his voice had already elevated in volume. “We here!” Mahomes shouted. “We’re (bleeping) here!” Here, for the first time in Mahomes’ playoff career, actually meant just the opposite. There. On the road. The Chiefs have reached the Super Bowl for the fourth time in five seasons — but their path in these playoffs has been markedly different than the previous trips. Unexpected, even. They are underdogs, lit…