libsel4utils: Add additional headers to IRQ server

As part of the refactoring, the IRQ server library now requires these
headers.

libsel4utils/include/sel4utils/irq_server.h

diff --git a/libsel4utils/include/sel4utils/irq_server.h b/libsel4utils/include/sel4utils/irq_server.h
index 61ba043..3e6f472 100644
--- a/libsel4utils/include/sel4utils/irq_server.h
+++ b/libsel4utils/include/sel4utils/irq_server.h
@@ -56,6 +56,9 @@
 #include <vspace/vspace.h>
 #include <vka/vka.h>
 #include <simple/simple.h>
+#include <platsupport/io.h>
+#include <platsupport/irq.h>
+#include <sel4platsupport/irq.h>
 
 typedef int irq_t;