arch/tile: export only COMMAND_LINE_SIZE to userspace.

This fixes a failure in "make headers_check" for tile.
I hadn't realized this file was exported to userspace by default.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

arch/tile/include/asm/setup.h

@@ -15,6 +15,10 @@
 #ifndef _ASM_TILE_SETUP_H
 #define _ASM_TILE_SETUP_H
 
+#define COMMAND_LINE_SIZE	2048
+
+#ifdef __KERNEL__
+
 #include <linux/pfn.h>
 #include <linux/init.h>
 
@@ -23,10 +27,10 @@
  */
 #define MAXMEM_PFN	PFN_DOWN(MAXMEM)
 
-#define COMMAND_LINE_SIZE	2048
-
 void early_panic(const char *fmt, ...);
 void warn_early_printk(void);
 void __init disable_early_printk(void);
 
+#endif /* __KERNEL__ */
+
 #endif /* _ASM_TILE_SETUP_H */