chore: drop hf_interrupt_inject

This is a legacy interface no longer required in the
context of the SPMC.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: Ib56f66d0872ed2e01c609c9591531dd483ab7987
diff --git a/src/arch/aarch64/hypervisor/handler.c b/src/arch/aarch64/hypervisor/handler.c
index 6c1fa0f..0244eae 100644
--- a/src/arch/aarch64/hypervisor/handler.c
+++ b/src/arch/aarch64/hypervisor/handler.c
@@ -1076,12 +1076,7 @@
 	}
 
 	switch (args.func) {
-#if SECURE_WORLD == 0
-	case HF_INTERRUPT_INJECT:
-		vcpu->regs.r[0] = api_interrupt_inject(args.arg1, args.arg2,
-						       args.arg3, vcpu, &next);
-		break;
-#else
+#if SECURE_WORLD == 1
 	case HF_INTERRUPT_DEACTIVATE:
 		vcpu->regs.r[0] = plat_ffa_interrupt_deactivate(
 			args.arg1, args.arg2, vcpu);