msm: cpufreq: fix a race between hotplug and cpufreq

When msm_cpufreq_target() is called without holding the policy
semaphore, there is a rare chance that the cpu gets hotplugged in
the acpuclk_set_rate. The probability of this issue increases
when cross-calling is used or using interactive governor which
tries to set all cpu frequencies from a single thread.

Add a hotplug notifier and set the device_suspended flag holding
the suspend mutex, when cpu is going down. This mutex is always
held when frequency changes are done.

Change-Id: Ide3aa6927ad60d2512d63761c51bb15117461250
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
(cherry picked from commit 56f5a6de7f2ab48ed0538da727ad52673fb801a2)

Signed-off-by: Sudhir Sharma <sudsha@codeaurora.org>
msm: cpufreq: Remove cross-calling limitation

Remove cross-calling limitations imposed by cpufreq. Clock drivers
and SPM driver now allow changing of frequencies from any core. Using
cpus_allowed mask to check for core affinity works well with workqueues
but do not port so well when the core requesting frequency change is a
kthread with the flag PF_TASK_BOUND not set.

Change-Id: Iab664ce8657780814440a11dff77cc925df597f8
Signed-off-by: Praveen Chidambaram <pchidamb@codeaurora.org>
(cherry picked from commit be01a17afb6b6e85456217caa1ac11eb0b6674e1)
(cherry picked from commit bd97cdfeb87eda0373721baaea744b02a27822f5)