clk: qcom: debugcc-shima: Remove measure support for unregistered clocks

Remove debug measure support for clocks that are not registered with the
clock framework. While at it update the external clocks in debugcc to
measure only clocks.

Change-Id: Icd6d59a098d116074403d24d9bc990fdebd7bdd7
Signed-off-by: Jagadeesh Kona <jkona@codeaurora.org>