[S390] irq: merge irq.c and s390_ext.c

Merge irq.c and s390_ext.c into irq.c. That way all external interrupt
related functions are together.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index a15c015..7f91249 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -54,7 +54,7 @@
 #include <asm/atomic.h>
 #include <asm/ebcdic.h>
 #include <asm/io.h>
-#include <asm/s390_ext.h>
+#include <asm/irq.h>
 #include <asm/smp.h>
 
 /*