msm: camera: icp: Use src clk index to populate clk rates

Using last clk index doesn't gaurantee the src clock rates
are populated properly, instead use src clock index which
is already saved pointing to the correct src clock array.

Change-Id: I90369bd2d0aefed74ba738a0deb5768d43e6e576
Signed-off-by: Jigarkumar Zala <jzala@codeaurora.org>