msm: hotplug: Return early if already enabled

* In case user/script tries to send same value again to msm_enabled,
  return early.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>
msm: thermal: Ammend waiting for completion

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: Dan Trifan <jimsth@gmail.com>