cpufreq: don't allow governor limits to be changed when it is disabled

__cpufreq_governor() returns with -EBUSY when governor is already
stopped and we try to stop it again, but when it is stopped we must
not allow calls to CPUFREQ_GOV_LIMITS event as well.

This patch adds this check in __cpufreq_governor().

Bug 1371564

Reported-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit f73d39338444d9915c746403bd98b145ff9d2ba4)
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Change-Id: Iba25d40c8bc12d7030e60d35b0fa1a6042ebeacf
Reviewed-on: http://git-master/r/309652
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Tested-by: Bharat Nihalani <bnihalani@nvidia.com>

Conflicts:
	drivers/cpufreq/cpufreq.c