ext: Fix warnings in vl53l0x ST library when compiling on Zephyr

Warning are present in the default ST source code, fix them here.

Signed-off-by: Vincent Veron <vincent.veron@st.com>
diff --git a/ext/hal/st/lib/sensor/vl53l0x/api/core/src/vl53l0x_api.c b/ext/hal/st/lib/sensor/vl53l0x/api/core/src/vl53l0x_api.c
index 0163f73..d632146 100644
--- a/ext/hal/st/lib/sensor/vl53l0x/api/core/src/vl53l0x_api.c
+++ b/ext/hal/st/lib/sensor/vl53l0x/api/core/src/vl53l0x_api.c
@@ -1793,7 +1793,7 @@
 	VL53L0X_Error Status = VL53L0X_ERROR_NONE;
 	uint8_t EnableZeroValue = 0;
 	uint16_t Temp16;
-	FixPoint1616_t TempFix1616;
+	FixPoint1616_t TempFix1616=0;
 
 	LOG_FUNCTION_START("");
 
@@ -2718,7 +2718,7 @@
 	VL53L0X_InterruptPolarity *pPolarity)
 {
 	VL53L0X_Error Status = VL53L0X_ERROR_NONE;
-	VL53L0X_GpioFunctionality GpioFunctionality;
+	VL53L0X_GpioFunctionality GpioFunctionality = VL53L0X_GPIOFUNCTIONALITY_OFF;
 	uint8_t data;
 
 	LOG_FUNCTION_START("");