clk: qcom: npucc-sm8150: specify external parents for NPU_CC branch clocks

Several NPU_CC branch clocks have a parent which is external to
NPU_CC.  Specify these parents in the NPU_CC driver in order to
avoid clock stuck on warnings if one of the parent clocks is
disabled before its child.

Change-Id: I96e6ae11243b895cf05fa4d12e1acaf3d6bbe873
Signed-off-by: David Collins <collinsd@codeaurora.org>