feat(spmd): introduce platform handler for Group0 interrupt

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

Moreover, this patch also provides a dummy implementation of the
above mentioned platform hook for QEMU, corstone100, n1sdp and
hikey960 ports.

Change-Id: I01d3451408f47ac313b0af74046cce89f89b85bb
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/plat/arm/board/n1sdp/n1sdp_bl31_setup.c b/plat/arm/board/n1sdp/n1sdp_bl31_setup.c
index 4941a4b..6809541 100644
--- a/plat/arm/board/n1sdp/n1sdp_bl31_setup.c
+++ b/plat/arm/board/n1sdp/n1sdp_bl31_setup.c
@@ -159,3 +159,14 @@
 	if ((plat_info.multichip_mode) && (plat_info.remote_ddr_size != 0))
 		remote_dmc_ecc_setup(plat_info.remote_ddr_size);
 }
+
+#if defined(SPD_spmd)
+/*
+ * A dummy implementation of the platform handler for Group0 secure interrupt.
+ */
+int plat_spmd_handle_group0_interrupt(uint32_t intid)
+{
+	(void)intid;
+	return -1;
+}
+#endif /*defined(SPD_spmd)*/