cpuidle: Fix cpuidle_driver_state_disabled()

It turns out that cpuidle_driver_state_disabled() can be called
before registering the cpufreq driver on some platforms, which
was not expected when it was introduced and which leads to a NULL
pointer dereference when trying to walk the CPUs associated with
the given cpuidle driver.

Fix the problem by making cpuidle_driver_state_disabled() check if
the driver's mask of CPUs associated with it is present and to set
CPUIDLE_FLAG_UNUSABLE for the given idle state in the driver's states
list if that is not the case to cause __cpuidle_register_device() to
set CPUIDLE_STATE_DISABLED_BY_DRIVER for that state for all cpuidle
devices registered by it later.

Fixes: cbda56d5 ("cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks")
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>