arm64: dts: qcom: milos: Add missing CX power domain to GCC

arm64: dts: qcom: milos: Add missing CX power domain to GCC

Unless CX is declared as the power-domain of GCC, votes (power and
performance) on the GDSCs it provides will not propagate to the CX,
which might result in under-voltage conditions.

Add the missing power-domains property to associate GCC with RPMHPD_CX.

Fixes: d9d59d105f98 ("arm64: dts: qcom: Add initial Milos dtsi")
Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260327-dt-fix-milos-eliza-gcc-power-domains-v1-2-f14a22c73fe9@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>