cpufreq: cpufreq-dt: Move newline to end of error message

Currently the error message is needlessly splitted across two lines.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>