mfd: Fix twl_has_pwrbutton typo

Change the typo CONFIG_INPUT_TWL4030_PWBUTTON_MODULE in the
twl_has_pwrbutton definition to CONFIG_INPUT_TWL4030_PWRBUTTON_MODULE.
Signed-off-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Signed-off-by: Christoph Egger <siccegge@stud.informatik.uni-erlangen.de>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/twl-core.c

@@ -123,7 +123,7 @@
 #define TWL_NUM_SLAVES		4
 
 #if defined(CONFIG_INPUT_TWL4030_PWRBUTTON) \
-	|| defined(CONFIG_INPUT_TWL4030_PWBUTTON_MODULE)
+	|| defined(CONFIG_INPUT_TWL4030_PWRBUTTON_MODULE)
 #define twl_has_pwrbutton()	true
 #else
 #define twl_has_pwrbutton()	false