dt-bindings: power: qcom,rpmpd: Add SC8280XP_MXC_AO

Not sure how useful it's gonna be in practice, but the definition is
missing (unlike the previously-unused SC8280XP_MXC-non-_AO), so add it
to allow the driver to create the corresponding pmdomain.

Fixes: dbfb5f9 ("dt-bindings: power: rpmpd: Add sc8280xp RPMh power-domains")
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20251202-topic-8280_mxc-v2-1-46cdf47a829e@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: quic-kdybcio

include/dt-bindings/power/qcom,rpmhpd.h

@@ -264,5 +264,6 @@
 #define SC8280XP_NSP		13
 #define SC8280XP_QPHY		14
 #define SC8280XP_XO		15
+#define SC8280XP_MXC_AO		16
 
 #endif