The clock source for MSM8916 cpu cores is like below.

                        |\
         a53pll --------| \ a53mux     +------+
                        | |------------| cpus |
     gpll0_vote --------| /            +------+
                        |/

So a53mux rather than a53pll is actually the parent clock of cpu cores.
It makes more sense to flag a53mux as critical instead, so that when
either a53pll or gpll0_vote is used by cpu cores, the clock will be kept
enabled while the other can be disabled.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20210704024032.11559-2-shawn.guo@linaro.orgSigned-off-by: Stephen Boyd <sboyd@kernel.org>