clk: qcom: gcc-sm8150: Remove the parent field for gcc_npu_axi_clk

The gcc_npu_axi_clk_src RCG is under RPMh control and HLOS has
no way to vote on it. Hence remove it as the listed parent for
the gcc_npu_axi_clk clock.

Change-Id: Idd3b430375916cad9d0e474322b3ebf183ebfc1d
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>