powerpc: Rename exception.h to exception-64s.h

The file include/asm/exception.h contains definitions
that are specific to exception handling on 64-bit server
type processors.

This renames the file to exception-64s.h to reflect that
fact and avoid confusion.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/exceptions-64s.S

@@ -12,6 +12,8 @@
  *
  */
 
+#include <asm/exception-64s.h>
+
 /*
  * We layout physical memory as follows:
  * 0x0000 - 0x00ff : Secondary processor spin code

arch/powerpc/kernel/head_64.S

@@ -36,7 +36,6 @@
 #include <asm/thread_info.h>
 #include <asm/firmware.h>
 #include <asm/page_64.h>
-#include <asm/exception.h>
 #include <asm/irqflags.h>
 
 /* The physical memory is layed out such that the secondary processor

arch/powerpc/platforms/iseries/exception.h

@@ -24,7 +24,7 @@
  *  as published by the Free Software Foundation; either version
  *  2 of the License, or (at your option) any later version.
  */
-#include <asm/exception.h>
+#include <asm/exception-64s.h>
 
 #define EXCEPTION_PROLOG_ISERIES_1					\
 	mfmsr	r10;							\