pmdomain: qcom: rpmhpd: Add MXC to SC8280XP

This was apparently accounted for in dt-bindings, but never made its
way into the driver.

Fix it for SC8280XP and its VDD_GFX-less cousin, SA8540P.

Fixes: f68f1cb3437d ("soc: qcom: rpmhpd: add sc8280xp & sa8540p rpmh power-domains")
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Signed-off-by: Konrad Dybcio <[e-mail]>
Reviewed-by: Ulf Hansson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/pmdomain/qcom/rpmhpd.c

···
 	[SC8280XP_MMCX_AO] = &mmcx_ao,
 	[SC8280XP_MX] = &mx,
 	[SC8280XP_MX_AO] = &mx_ao,
+	[SC8280XP_MXC] = &mxc,
+	[SC8280XP_MXC_AO] = &mxc_ao,
 	[SC8280XP_NSP] = &nsp,
 };
 
···
 	[SC8280XP_MMCX_AO] = &mmcx_ao,
 	[SC8280XP_MX] = &mx,
 	[SC8280XP_MX_AO] = &mx_ao,
+	[SC8280XP_MXC] = &mxc,
+	[SC8280XP_MXC_AO] = &mxc_ao,
 	[SC8280XP_NSP] = &nsp,
 	[SC8280XP_QPHY] = &qphy,
 };