modbus_get_float_abcd - get a float value from 2 registers in ABCD byte order
float modbus_get_float_abcd(const uint16_t *src);The modbus_get_float_abcd() function shall get a float from 4 bytes in usual
Modbus format. The src array must be a pointer on two 16 bits values, for
example, if the first word is set to 0x0020 and the second to 0xF147, the float
value will be read as 123456.0.
The function shall return a float.