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/bug.h

@@ -0,0 +1,22 @@
+#ifndef _SPARC_BUG_H
+#define _SPARC_BUG_H
+
+#ifdef CONFIG_BUG
+#include <linux/compiler.h>
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+extern void do_BUG(const char *file, int line);
+#define BUG() do {					\
+	do_BUG(__FILE__, __LINE__);			\
+	__builtin_trap();				\
+} while (0)
+#else
+#define BUG()		__builtin_trap()
+#endif
+
+#define HAVE_ARCH_BUG
+#endif
+
+#include <asm-generic/bug.h>
+
+#endif