UPSTREAM: cpufreq: schedutil: Refactor sugov_next_freq_shared()

The loop in sugov_next_freq_shared() contains an if block to skip the
loop for the current CPU. This turns out to be an unnecessary
conditional in the scheduler's hot-path for every CPU in the policy.

It would be better to drop the conditional and make the loop treat all
the CPUs in the same way. That would eliminate the need of calling
sugov_iowait_boost() at the top of the routine.

To keep the code optimized to return early if the current CPU has RT/DL
flags set, move the flags check to sugov_update_shared() instead in
order to avoid the function call entirely.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit cba1dfb57b94c234728b689d9b00d4267fa1a879)
(modified for SCHED_CPUFREQ_DL vs SCHED_CPUFREQ_RT)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Change-Id: Ie046fdc8eda46821356750edd0fb6f7d077af363
Signed-off-by: Quentin Perret <quentin.perret@arm.com>