arm: mxs: Remove misleading comments

Both comments look like being copy & paste errors.

Signed-off-by: Michael Heimpold <michael.heimpold@i2se.com>
Cc: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Peng Fan <peng.fan@nxp.com>