clk: qcom: debugcc: Add clock measure support for cnoc and snoc clk

Add support for measure_only_snoc_clk and measure_only_cnoc_clk to
measure the frequency of gcc_sys_noc_axi_clk and gcc_cfg_noc_ahb_clk
clock. Also update the offset of period register to measure DDR frequency.

Change-Id: I1350284cb1dedd4bfb15702a37043caff80fad72
Signed-off-by: Naveen Yadav <naveenky@codeaurora.org>