arm: Fix typo in ldrsh instruction name
arm: Fix typo in ldrsh instruction name

ldrsh was typoed as hdrsh, which is a bit annoying when printing
instructions.  This patch fixes it.
(transplanted from 43b5dd939a49b3d3c321c2b4fa8704045af8e45f)

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin