PM / devfreq: Remove dependencies between sysfs nodes and suspend count

This change reverts commit 5e33579a ("devfreq: Do not allow tunable
updates when device is suspended") and commit db4f4a09 ("PM/devfreq:
Do not switch governors from sysfs when device is suspended").

Userspace updates to sysfs nodes like governor and polling_interval are
currently not allowed when there is a non-zero suspend count. This
requirement existed in the past due to hardware dependencies in some
devfreq drivers. However, these hardware dependencies should be handled
by the relevant devfreq drivers rather than the devfreq framework so
remove the suspend count checks in these devfreq framework sysfs APIs.

Change-Id: I8010b519d72784a6b90955acc7899c1a520aa7e7
Signed-off-by: Amir Vajid <avajid@codeaurora.org>