PM / devfreq: Fix a typo in a comment

'govenror' was used in place of 'governor'
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/governor.h

@@ -30,7 +30,7 @@
  * @node:		list node - contains registered devfreq governors
  * @name:		Governor's name
  * @immutable:		Immutable flag for governor. If the value is 1,
- *			this govenror is never changeable to other governor.
+ *			this governor is never changeable to other governor.
  * @interrupt_driven:	Devfreq core won't schedule polling work for this
  *			governor if value is set to 1.
  * @get_target_freq:	Returns desired operating frequency for the device.