[2.0.x] Correct step pulse width on LPC1768, DUE & Teensy35_36 (#10016)

Marlin/src/HAL/HAL_DUE/HAL_timers_Due.h

 #define TONE_TIMER_NUM 6  // index of timer to use for beeper tones
 
 #define HAL_TIMER_RATE         ((F_CPU) / 2)    // frequency of timers peripherals
-#define STEPPER_TIMER_PRESCALE 1.0              // prescaler for setting stepper frequency
+#define STEPPER_TIMER_PRESCALE (CYCLES_PER_MICROSECOND / HAL_TICKS_PER_US)
 #define HAL_STEPPER_TIMER_RATE HAL_TIMER_RATE   // frequency of stepper timer (HAL_TIMER_RATE / STEPPER_TIMER_PRESCALE)
 #define HAL_TICKS_PER_US       ((HAL_STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs
 

Marlin/src/HAL/HAL_LPC1768/HAL_timers.h

 #define TEMP_TIMER_NUM 1  // index of timer to use for temperature
 
 #define HAL_TIMER_RATE         ((SystemCoreClock) / 4)  // frequency of timers peripherals
-#define STEPPER_TIMER_PRESCALE 1.0              // prescaler for setting stepper frequency
+#define STEPPER_TIMER_PRESCALE (CYCLES_PER_MICROSECOND / HAL_TICKS_PER_US)
 #define HAL_STEPPER_TIMER_RATE HAL_TIMER_RATE   // frequency of stepper timer (HAL_TIMER_RATE / STEPPER_TIMER_PRESCALE)
 #define HAL_TICKS_PER_US       ((HAL_STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs
 #define HAL_TEMP_TIMER_RATE    1000000

Marlin/src/HAL/HAL_TEENSY35_36/HAL_timers_Teensy.h

 #define FTM1_TIMER_RATE (F_BUS / FTM1_TIMER_PRESCALE) // 60MHz / 4 = 15MHz
 
 #define STEPPER_TIMER STEP_TIMER_NUM // Alias?
-#define STEPPER_TIMER_PRESCALE 0 // Not defined anywhere else!
+#define STEPPER_TIMER_PRESCALE (CYCLES_PER_MICROSECOND / HAL_TICKS_PER_US)
 
 #define PULSE_TIMER_NUM STEP_TIMER_NUM
 #define PULSE_TIMER_PRESCALE STEPPER_TIMER_PRESCALE