ARM: dts: msm: Update npu clocks

This change is to add dsp_core_clk_src to npu clocks and remove
all othere dsp related clocks. And it removes clock frequency
settings for MINSVS mode.

Change-Id: I4141ff15d6aff4ecf55598863eb2aab81ea6fbcb
Signed-off-by: Jilai Wang <jilaiw@codeaurora.org>