pwm: lpss: Update PWM setting for Broxton

For Broxton PWM controller, base unit is defined as 8-bit integer
and 14-bit fraction, so need to update base unit setting to output
wave with right frequency.

Signed-off-by: Qipeng Zha <qipeng.zha@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-lpss.h

@@ -21,6 +21,7 @@ struct pwm_lpss_chip;
 struct pwm_lpss_boardinfo {
 	unsigned long clk_rate;
 	unsigned int npwm;
+	unsigned long base_unit_bits;
 };
 
 extern const struct pwm_lpss_boardinfo pwm_lpss_byt_info;