As a symbolic polynomial...
syms x
sp = x.^(0:(numel(v)-1))*v.'
sp =
3*x^2 + 2*x + 1
As a function handle that uses polyval:
f = @(x) polyval(flip(v),x);
f(0:5)
ans =
1 6 17 34 57 86
As you can see, it is even vectorized. Note that I had to flip the coefficients vector, since polyval presumes the coefficients start from the highest order term, then go in decreasing order.
Of course, you can just use polyval directly too.
If you want to, it is not even that difficult to avoid use of polyval completely, but I'll stop here, as this does answer your immediate question.