Add a mailbox channel declaration to the AON firmware node to describe
the mailbox channel assigned to the SBI firmware to communicate with
AON.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>
---
 arch/riscv/boot/dts/thead/th1520.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/boot/dts/thead/th1520.dtsi b/arch/riscv/boot/dts/thead/th1520.dtsi
index 136ebe210b876..6e5e0223d0c16 100644
--- a/arch/riscv/boot/dts/thead/th1520.dtsi
+++ b/arch/riscv/boot/dts/thead/th1520.dtsi
@@ -233,8 +233,8 @@ stmmac_axi_config: stmmac-axi-config {
 
 	aon: aon {
 		compatible = "thead,th1520-aon";
-		mboxes = <&mbox_910t 1>;
-		mbox-names = "aon";
+		mboxes = <&mbox_910t 1>, <&mbox_910r 1>;
+		mbox-names = "aon", "aon-for-sbi";
 		resets = <&rst TH1520_RESET_ID_GPU_CLKGEN>;
 		reset-names = "gpu-clkgen";
 		#power-domain-cells = <1>;
-- 
2.50.1