imx: mx6: correct get_cpu_speed_grade_hz for i.MX6DQP

Correct get_cpu_speed_grade_hz for i.MX6DQP, otherwise we
will get wrong speed grade info i.MX6DQP.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
1 file changed