greybus: pwm: Fix compilation with v4.3 kernel

pwm_is_enabled() wasn't enabled by v4.2-rc1, but it was based of
v4.2-rc1. It was actually first included in v4.3.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/kernel_ver.h

@@ -328,10 +328,10 @@ static inline void reinit_completion(struct completion *x)
 }
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
 #include <linux/pwm.h>
 /*
- * pwm_is_enabled() was first defined in 4.2-rc1 (first commit!).
+ * pwm_is_enabled() was first defined in 4.3.
  * PWMF_ENABLED was first defined in 3.5-rc2, but our code is
  * always newer than that.
 */