The devfreq using passive governor is not able to change the governor.
So, the user can not change the governor through 'available_governor' sysfs
entry. Also, the devfreq which don't use the passive governor is not able to
change to 'passive' governor on the fly.

Fixes: 996133119f57 ("PM / devfreq: Add new passive governor")
Cc: stable@vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq.c          | 31 +++++++++++++++++++++++++++----
 drivers/devfreq/governor_passive.c |  1 +
 include/linux/devfreq.h            |  3 +++
 3 files changed, 31 insertions(+), 4 deletions(-)

Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Applying to for-next.