NRF52: Fix PWM driver

Looks like there is a bug in function `pwmout_pulsewidth()`.
The function should check if given puls with is not greater than configured period. 

Author: mprse

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/pwmout_api.c

@@ -295,9 +295,9 @@ void pwmout_period_us(pwmout_t *obj, int period)
 void pwmout_pulsewidth(pwmout_t *obj, float pulse)
 {
     DEBUG_PRINTF("pwmout_pulsewidt: %f\r\n", pulse);
-
+    
     /* Cap pulsewidth to period before setting it. */
-    if ((pulse * 1000000) > (float) (obj->pulse & ~SEQ_POLARITY_BIT)) {
+    if ((pulse * 1000000) > (float) obj->period) {
         obj->pulse &= SEQ_POLARITY_BIT;
         obj->pulse |= obj->period;
         pwmout_pulsewidth_us(obj, obj->pulse);
@@ -354,4 +354,3 @@ const PinMap *pwmout_pinmap()
 }
 
 #endif // DEVICE_PWMOUT
-