add f64_square helper function

Author: hrfarmer

FprimeZephyrReference/Components/Drv/Helpers/Helpers.cpp

@@ -13,4 +13,8 @@ F64 sensor_value_to_f64(const struct sensor_value& val) {
     return val.val1 + (val.val2 / 1000000.0f);
 }
 
+F64 f64_square(float num) {
+    return num * num;
+}
+
 }  // namespace Drv

FprimeZephyrReference/Components/Drv/Helpers/Helpers.hpp

@@ -14,6 +14,9 @@ namespace Drv {
 //! Convert a Zephyr sensor_value to an Fprime F64
 F64 sensor_value_to_f64(const struct sensor_value& val);
 
+//! Square a float
+F64 f64_square(float num);
+
 }  // namespace Drv
 
 #endif