cpufreq: imx6q: Unconditionally call dev_pm_opp_of_remove_table()

dev_pm_opp_of_remove_table() doesn't report any errors when it fails to
find the OPP table with error -ENODEV (i.e. OPP table not present for
the device). And we can call dev_pm_opp_of_remove_table()
unconditionally here.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>