feat(rdn2): introduce platform handler for Group0 interrupt

This patch introduces a handler for RDN2 platform to triage Group0
secure interrupts. Currently, it is empty but serves as a
placeholder for future Group0 interrupt sources.

Signed-off-by: Nishant Sharma <nishant.sharma@arm.com>
Change-Id: If0b64e507e9105813d9a5d16f70101cf0d8ca5a4
diff --git a/plat/arm/board/rdn2/rdn2_plat.c b/plat/arm/board/rdn2/rdn2_plat.c
index fc016ae..f117456 100644
--- a/plat/arm/board/rdn2/rdn2_plat.c
+++ b/plat/arm/board/rdn2/rdn2_plat.c
@@ -169,4 +169,14 @@
 {
 	return 0;
 }
+
+int plat_spmd_handle_group0_interrupt(uint32_t intid)
+{
+	/*
+	 * As of now, there are no sources of Group0 secure interrupt enabled
+	 * for RDN2.
+	 */
+	(void)intid;
+	return -1;
+}
 #endif