cpufreq: interactive: Make skipping delay for migration optional

Commit 92352c0a65bc ("cpufreq: interactive: Ramp up directly if
cpu_load exceeds 100") and commit 594945e67031 ("cpufreq: interactive:
Skip delay in frequency changes due to migration") allow interactive
governor to skip above_hispeed_delay and min_sample_time if the
frequency evaluation request comes from scheduler. Power and performance
benefits of these two features are dependent on the behavior of each
workload. Adverse load pattern may experience regression instead of
improvement.

Make both features optional by introducing a sysfs file for each. Both
features are disabled by default.

Change-Id: I394c7fac00e6b20259dd198bd526a32ead54f14e
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>