pwm: lpss: Add a comment to the bypass field

Add a comment to the bypass field based on the commit b997e3ed
("pwm: lpss: Set enable-bit before waiting for update-bit
to go low").
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-lpss.h

@@ -25,6 +25,11 @@ struct pwm_lpss_boardinfo {
 	unsigned long clk_rate;
 	unsigned int npwm;
 	unsigned long base_unit_bits;
+	/*
+	 * Some versions of the IP may stuck in the state machine if enable
+	 * bit is not set, and hence update bit will show busy status till
+	 * the reset. For the rest it may be otherwise.
+	 */
 	bool bypass;
 	/*
 	 * On some devices the _PS0/_PS3 AML code of the GPU (GFX0) device