PM / devfreq: correct Kconfig dependency

config ARCH_HAS_DEVFREQ

	bool

	depends on ARCH_HAS_OPP

	help

	  Denotes that the architecture supports DEVFREQ. If the architecture

	  supports multiple OPP entries per device and the frequency of the

	  devices with OPPs may be altered dynamically, the architecture

	  supports DEVFREQ.

menuconfig PM_DEVFREQ

	bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support"

	depends on PM_OPP && ARCH_HAS_DEVFREQ

	help

	  With OPP support, a device may have a list of frequencies and

	  voltages available. DEVFREQ, a generic DVFS framework can be

	  registered for a device with OPP support in order to let the

	  governor provided to DEVFREQ choose an operating frequency

	  based on the OPP's list and the policy given with DEVFREQ.

	  A device may have a list of frequencies and voltages available.

	  devfreq, a generic DVFS framework can be registered for a device

	  in order to let the governor provided to devfreq choose an

	  operating frequency based on the device driver's policy.

	  Each device may have its own governor and policy. DEVFREQ can

	  Each device may have its own governor and policy. Devfreq can

	  reevaluate the device state periodically and/or based on the

	  OPP list changes (each frequency/voltage pair in OPP may be

	  disabled or enabled).

	  notification to "nb", a notifier block, of devfreq.

	  Like some CPUs with CPUFREQ, a device may have multiple clocks.

	  Like some CPUs with CPUfreq, a device may have multiple clocks.

	  However, because the clock frequencies of a single device are

	  determined by the single device's state, an instance of DEVFREQ

	  determined by the single device's state, an instance of devfreq

	  is attached to a single device and returns a "representative"

	  clock frequency from the OPP of the device, which is also attached

	  to a device by 1-to-1. The device registering DEVFREQ takes the

	  responsiblity to "interpret" the frequency listed in OPP and

	  clock frequency of the device, which is also attached

	  to a device by 1-to-1. The device registering devfreq takes the

	  responsiblity to "interpret" the representative frequency and

	  to set its every clock accordingly with the "target" callback

	  given to DEVFREQ.

	  given to devfreq.

	  When OPP is used with the devfreq device, it is recommended to

	  register devfreq's nb to the OPP's notifier head.  If OPP is

	  used with the devfreq device, you may use OPP helper

	  functions defined in devfreq.h.

if PM_DEVFREQ