If \(f(x), g(x), h(x)\) and \(f'(x)\) are polynomials in \(x\), and\(\left(\int_1^x f(x)h(x) dx\right) \left(\int_1^x g(x)f'(x) dx\right) - \left(\int_1^x f(x)f'(x) dx\right) \left(\int_1^x g(x)h(x) dx\right)\)is divisible by \((x-1)^l\), find the maximum value of \(l\).