AP_ADC: fix compile warnings re float constants

libraries/AP_ADC/AP_ADC_ADS1115.cpp

@@ -37,14 +37,14 @@
 #define ADS1115_PGA_0P256B          0x06 << ADS1115_PGA_SHIFT
 #define ADS1115_PGA_0P256C          0x07 << ADS1115_PGA_SHIFT
 
-#define ADS1115_MV_6P144            0.187500
-#define ADS1115_MV_4P096            0.125000
-#define ADS1115_MV_2P048            0.062500 // default
-#define ADS1115_MV_1P024            0.031250
-#define ADS1115_MV_0P512            0.015625
-#define ADS1115_MV_0P256            0.007813
-#define ADS1115_MV_0P256B           0.007813
-#define ADS1115_MV_0P256C           0.007813
+#define ADS1115_MV_6P144            0.187500f
+#define ADS1115_MV_4P096            0.125000f
+#define ADS1115_MV_2P048            0.062500f // default
+#define ADS1115_MV_1P024            0.031250f
+#define ADS1115_MV_0P512            0.015625f
+#define ADS1115_MV_0P256            0.007813f
+#define ADS1115_MV_0P256B           0.007813f
+#define ADS1115_MV_0P256C           0.007813f
 
 #define ADS1115_MODE_SHIFT          8
 #define ADS1115_MODE_CONTINUOUS     0x00 << ADS1115_MODE_SHIFT

libraries/AP_ADC/AP_ADC_HIL.cpp

@@ -27,7 +27,7 @@ const int8_t AP_ADC_HIL::sensorSign[6]  = { 1, -1, -1,-1,  1,  1};
 const float AP_ADC_HIL::gyroBias[3]     = {1665,1665,1665};
 const float AP_ADC_HIL::accelBias[3]    = {2025,2025,2025};
 // gyroScale = 1/[GyroGain*pi/180]   GyroGains (0.4,0.41,0.41)
-const float AP_ADC_HIL::gyroScale[3] = {143.239, 139.746, 139.746};
+const float AP_ADC_HIL::gyroScale[3] = {143.239f, 139.746f, 139.746f};
 const float AP_ADC_HIL::accelScale[3] = {418,418,418}; // adcPerG
     
 AP_ADC_HIL::AP_ADC_HIL()