fvp: add secure UART interrupt in device region

OP-TEE enables the use case of a secure interrupt triggered by the UART
driver. This interrupt is routed by FFA_INTERRUPT interface to OP-TEE.
Define the UART interrupt in the FF-A device region node.

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/fvp/optee_sp_manifest.dts b/fvp/optee_sp_manifest.dts
index 6bdc04c..0373bfe 100644
--- a/fvp/optee_sp_manifest.dts
+++ b/fvp/optee_sp_manifest.dts
@@ -49,6 +49,7 @@
 			base-address = <0x00000000 0x1c0a0000>;
 			pages-count = <1>;
 			attributes = <0x3>; /* read-write */
+			interrupts = <38 0x900>;
 		};
 	};
 };