clk: qcom: gcc: Add support for Secure control source clock

The secure controller driver requires to request for various frequencies
on the source clock, thus add support for the same.

Signed-off-by: Taniya Das <tdas@codeaurora.org>
Link: https://lkml.kernel.org/r/1589709861-27580-4-git-send-email-tdas@codeaurora.org


Signed-off-by: Stephen Boyd <sboyd@kernel.org>