clk: qcom: gpu_cc_gmu_clk_src has 5 parents, not 6

In an earlier version of commit 453361cd ("clk: qcom: Add graphics
clock controller driver for SDM845") there were 6 listed parents for
"gpu_cc_gmu_clk_src".  In the version that landed there were 5.
...but "num_parents" was still left at 6.  On my system this goes boom
at bootup.

Fixes: 453361cd ("clk: qcom: Add graphics clock controller driver for SDM845")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>