UPSTREAM: cpufreq: schedutil: Use unsigned int for iowait boost

Make iowait_boost and iowait_boost_max as unsigned int since its unit is kHz
and this is consistent with struct cpufreq_policy. Also change the local
variables in sugov_iowait_boost to match this.

Change-Id: I6c67ed94c57c4bdb24bada4b97045593fcb95d2e
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes <joelaf@google.com>