feat(setup-cfg): Add make flags for IRQ controller to the cfg

This commit adds a irq_flags variable as an output of the setup-cfg.
These flags are filled according to the platform arch.

pkgs/setup-cfg/setup-cfg.nix

@@ -7,6 +7,9 @@
     , bao-tests ? " " 
     , tests_srcs ? " " 
     , baremetal_patch ? " " 
+    , GIC_VERSION ? " "
+    , IRQC ? " "
+    , IPIC ? " "
 }:
 let
     platforms-arch = {
@@ -43,4 +46,8 @@ in {
     bao-tests = bao-tests;
     tests_srcs = tests_srcs;
     baremetal_patch = baremetal_patch;
+
+    irq_flags = if arch == "riscv64" then
+        "IRQC=${IRQC} IPIC=${IPIC}"
+    else "GIC_VERSION=${GIC_VERSION}"
 }