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/timex_64.h

@@ -0,0 +1,19 @@
+/*
+ * linux/include/asm/timex.h
+ *
+ * sparc64 architecture timex specifications
+ */
+#ifndef _ASMsparc64_TIMEX_H
+#define _ASMsparc64_TIMEX_H
+
+#include <asm/timer.h>
+
+#define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
+
+/* Getting on the cycle counter on sparc64. */
+typedef unsigned long cycles_t;
+#define get_cycles()	tick_ops->get_tick()
+
+#define ARCH_HAS_READ_CURRENT_TIMER
+
+#endif