sparc, sparc64: use arch/sparc/include

The majority of this patch was created by the following script:

***
ASM=arch/sparc/include/asm
mkdir -p $ASM
git mv include/asm-sparc64/ftrace.h $ASM
git rm include/asm-sparc64/*
git mv include/asm-sparc/* $ASM
sed -ie 's/asm-sparc64/asm/g' $ASM/*
sed -ie 's/asm-sparc/asm/g' $ASM/*
***

The rest was an update of the top-level Makefile to use sparc
for header files when sparc64 is being build.
And a small fixlet to pick up the correct unistd.h from
sparc64 code.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

arch/sparc/include/asm/hardirq_32.h

@@ -0,0 +1,23 @@
+/* hardirq.h: 32-bit Sparc hard IRQ support.
+ *
+ * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1998-2000 Anton Blanchard (anton@samba.org)
+ */
+
+#ifndef __SPARC_HARDIRQ_H
+#define __SPARC_HARDIRQ_H
+
+#include <linux/threads.h>
+#include <linux/spinlock.h>
+#include <linux/cache.h>
+
+/* entry.S is sensitive to the offsets of these fields */ /* XXX P3 Is it? */
+typedef struct {
+	unsigned int __softirq_pending;
+} ____cacheline_aligned irq_cpustat_t;
+
+#include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
+
+#define HARDIRQ_BITS    8
+
+#endif /* __SPARC_HARDIRQ_H */