sparc: fix sparse warnings in cpu_*.c

o declare variables from cpu_*.c
o declare function from cpu_32.c

To do this introduce a new header "kernel.h" which is local to kernel/

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index c8b03a4..555db74 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -52,6 +52,7 @@
 #endif
 
 #include "entry.h"
+#include "kernel.h"
 
 /* Used to synchronize accesses to NatSemi SUPER I/O chip configure
  * operations in asm/ns87303.h