sparc: fix sparc64 build due to leon.h inclusion

Stephen Rothwell <sfr@canb.auug.org.au> reported following error:
In file included from arch/sparc/kernel/prom_common.c:26:0:
arch/sparc/include/asm/leon.h:221:9: error: unknown type name 'irq_flow_handler_t'
arch/sparc/include/asm/leon.h:224:10: error: unknown type name 'irq_flow_handler_t'

Fix this by:
1) Avoid including leon.h in prom_commen.h (not needed)
2) Include irq.h in leon.h to avoid the missing symbol error
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/leon.h

@@ -213,6 +213,7 @@ struct leon3_cacheregs {
 	unsigned long dccr;	/* 0x0c - Data Cache Configuration Register */
 };
 
+#include <linux/irq.h>
 #include <linux/interrupt.h>
 
 struct device_node;

arch/sparc/kernel/prom_common.c

@@ -23,7 +23,6 @@
 #include <linux/of_pdt.h>
 #include <asm/prom.h>
 #include <asm/oplib.h>
-#include <asm/leon.h>
 
 #include "prom.h"