ARM: dts: qcom: msm8226: Add IMEM node

This enables userspace to signal the bootloader to go into the
bootloader or recovery mode.

The magic values can be found in both the downstream kernel and the LK
kernel (bootloader).
Signed-off-by: Matti Lehtimäki <matti.lehtimaki@gmail.com>
Reviewed-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230520121933.15533-5-matti.lehtimaki@gmail.com

arch/arm/boot/dts/qcom-msm8226.dtsi

@@ -647,6 +647,20 @@ smd-edge {
 				label = "lpass";
 			};
 		};
+
+		sram@fe805000 {
+			compatible = "qcom,msm8226-imem", "syscon", "simple-mfd";
+			reg = <0xfe805000 0x1000>;
+
+			reboot-mode {
+				compatible = "syscon-reboot-mode";
+				offset = <0x65c>;
+
+				mode-bootloader = <0x77665500>;
+				mode-normal     = <0x77665501>;
+				mode-recovery   = <0x77665502>;
+			};
+		};
 	};
 
 	timer {