x86: consolidate header guards

This patch is the result of an automatic script that consolidates the
format of all the headers in include/asm-x86/.

The format:

1. No leading underscore. Names with leading underscores are reserved.
2. Pathname components are separated by two underscores. So we can
   distinguish between mm_types.h and mm/types.h.
3. Everything except letters and numbers are turned into single
   underscores.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/include/asm-x86/i8253.h b/include/asm-x86/i8253.h
index b51c048..15a5b53 100644
--- a/include/asm-x86/i8253.h
+++ b/include/asm-x86/i8253.h
@@ -1,5 +1,5 @@
-#ifndef __ASM_I8253_H__
-#define __ASM_I8253_H__
+#ifndef ASM_X86__I8253_H
+#define ASM_X86__I8253_H
 
 /* i8253A PIT registers */
 #define PIT_MODE		0x43
@@ -15,4 +15,4 @@
 #define inb_pit		inb_p
 #define outb_pit	outb_p
 
-#endif	/* __ASM_I8253_H__ */
+#endif /* ASM_X86__I8253_H */