What you describe is racism, not white privilege.  The two are not synonymous.  White privilege suggests white people get certain benefits because they are white.  This is not the case.  With regard to police stopping your son, not getting stopped is the norm.  The fact that your black sons' get a negative version of the norm does not mean not white people are getting a positive version of the norm - rather the white person is just getting the norm.  

Just as a white man who looks poor is going to get the negative version of norm.  Not because he is white, but because he looks poor.

Racism exists and has existed.  But the saying the opposite is a privilege is just plain out false and unfounded.

I am, by the way, sorry that your sons get treated like this.