cpufreq: cpu0: use dev_{err|warn|dbg} instead of pr_{err|warn|debug}

We already have cpu_dev and is used at multiple places for printing errors using
dev_*(). But some prints are still using pr_*(). Lets make it consistent and
replace those pr_*() macros with dev_*() macros.

Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>