ARM: dts: msm: Add scc plls as fixed clocks for sm6150/sm8150

Add SCC PLLs as fixed clock because LPASS has ownership over
it and they are always enabled and running at fixed frequency.

Change-Id: I6c59b3398f652ebe4b4f48b5a25c9cd927c494d5
Signed-off-by: Veera Vegivada <vvegivad@codeaurora.org>