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/mmu_context_32.h

@@ -0,0 +1,42 @@
+#ifndef __SPARC_MMU_CONTEXT_H
+#define __SPARC_MMU_CONTEXT_H
+
+#include <asm/btfixup.h>
+
+#ifndef __ASSEMBLY__
+
+#include <asm-generic/mm_hooks.h>
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+/*
+ * Initialize a new mmu context.  This is invoked when a new
+ * address space instance (unique or shared) is instantiated.
+ */
+#define init_new_context(tsk, mm) (((mm)->context = NO_CONTEXT), 0)
+
+/*
+ * Destroy a dead context.  This occurs when mmput drops the
+ * mm_users count to zero, the mmaps have been released, and
+ * all the page tables have been flushed.  Our job is to destroy
+ * any remaining processor-specific state.
+ */
+BTFIXUPDEF_CALL(void, destroy_context, struct mm_struct *)
+
+#define destroy_context(mm) BTFIXUP_CALL(destroy_context)(mm)
+
+/* Switch the current MM context. */
+BTFIXUPDEF_CALL(void, switch_mm, struct mm_struct *, struct mm_struct *, struct task_struct *)
+
+#define switch_mm(old_mm, mm, tsk) BTFIXUP_CALL(switch_mm)(old_mm, mm, tsk)
+
+#define deactivate_mm(tsk,mm)	do { } while (0)
+
+/* Activate a new MM instance for the current task. */
+#define activate_mm(active_mm, mm) switch_mm((active_mm), (mm), NULL)
+
+#endif /* !(__ASSEMBLY__) */
+
+#endif /* !(__SPARC_MMU_CONTEXT_H) */