clk: qcom: Export clk_alpha_pll_configure()

This is used by the QCS404 GCC driver, export it to allow that driver to
be compiled as a module..

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>