read_current_timer() cleanups

- All implementations can be __devinit

- The function prototypes were in asm/timex.h but they all must be the same,
  so create a single declaration in linux/timex.h.

- uninline the sparc64 version to match the other architectures

- Don't bother #defining ARCH_HAS_READ_CURRENT_TIMER to a particular value.

[ezk@cs.sunysb.edu: fix build]
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/lib/delay_32.c b/arch/x86/lib/delay_32.c
index aad9d95..4535e6d 100644
--- a/arch/x86/lib/delay_32.c
+++ b/arch/x86/lib/delay_32.c
@@ -12,8 +12,10 @@
 
 #include <linux/module.h>
 #include <linux/sched.h>
+#include <linux/timex.h>
 #include <linux/preempt.h>
 #include <linux/delay.h>
+#include <linux/init.h>
 
 #include <asm/processor.h>
 #include <asm/delay.h>
@@ -63,7 +65,7 @@
 	delay_fn = delay_tsc;
 }
 
-int read_current_timer(unsigned long *timer_val)
+int __devinit read_current_timer(unsigned long *timer_val)
 {
 	if (delay_fn == delay_tsc) {
 		rdtscl(*timer_val);