AP_Motors: more changes for 32 bit servo mask

libraries/AP_Motors/AP_MotorsHeli_Dual.cpp

@@ -215,7 +215,7 @@ void AP_MotorsHeli_Dual::set_update_rate( uint16_t speed_hz )
     _speed_hz = speed_hz;
 
     // setup fast channels
-    uint16_t mask = 0;
+    uint32_t mask = 0;
     for (uint8_t i=0; i<AP_MOTORS_HELI_DUAL_NUM_SWASHPLATE_SERVOS; i++) {
         mask |= 1U << (AP_MOTORS_MOT_1+i);
     }

libraries/AP_Motors/AP_MotorsMatrix.cpp

@@ -117,7 +117,7 @@ void AP_MotorsMatrix::set_update_rate(uint16_t speed_hz)
     // record requested speed
     _speed_hz = speed_hz;
 
-    uint16_t mask = 0;
+    uint32_t mask = 0;
     for (uint8_t i = 0; i < AP_MOTORS_MAX_NUM_MOTORS; i++) {
         if (motor_enabled[i]) {
             mask |= 1U << i;

libraries/AP_Motors/AP_Motors_Class.h

@@ -309,10 +309,10 @@ protected:
     float               _air_density_ratio;     // air density / sea level density - decreases in altitude
 
     // mask of what channels need fast output
-    uint16_t            _motor_fast_mask;
+    uint32_t            _motor_fast_mask;
 
     // mask of what channels need to use SERVOn_MIN/MAX for output mapping
-    uint16_t            _motor_pwm_range_mask;
+    uint32_t            _motor_pwm_range_mask;
     
     // pass through variables
     float _roll_radio_passthrough;     // roll input from pilot in -1 ~ +1 range.  used for setup and providing servo feedback while landed