Magnitude calculation

Parameters:

x
y	source X and Y arrays
dst	destination array
len	length of arrays

// global functions

int
hal_ni_magnitude32f(
    const float* x,
    const float* y,
    float* dst,
    int len
    );

int
hal_ni_magnitude64f(
    const double* x,
    const double* y,
    double* dst,
    int len
    );