BugLink: http://bugs.launchpad.net/bugs/1520454

The driver may not be able to set the power correctly but that
is not a reason to BUG().
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
(cherry picked from commit 9d5de93f)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>