qcom-cpufreq: Block hotplug until cpufreq is ready

Hotplug before qcom-cpufreq is ready could lead to inconsistent CPU
clock state. Block hotplug by returning NOTIFY_BAD in hotplug callback
until qcom-cpufreq is probed.

Change-Id: I72a2f98c083c9b21b95ecafdb5a5be7a7682e842
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
Signed-off-by: revjunkie <gadgetjuan@gmail.com>
qcom-cpufreq: Fix hotplug blocking logic

Change 2b63b10 qcom-cpufreq: Block hotplug until cpufreq is ready
intended to block hotplug until qcom-cpufreq driver has got all
clocks. However, its implementation still leaves a small window when
CPU 0 has got its clock but others haven't. If a hotplug happens on
another CPU that doesn't have its clock pointer, refcount of that CPU
clock will again be wrong.

Fix the issue by introducing a ready flag.

Change-Id: I1e05b063b0584088f717b82709a3f1d55bc6561b
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>
Signed-off-by: revjunkie <gadgetjuan@gmail.com>