x86: unify include/asm-x86/linkage_[32|64].h

Remove definitions of FASTCALL/fastcall from linkage_32 as compiled with
-regparm=3 by default since 2.6.20 and should no longer be needed.

CONFIG X86_64 and CONFIG_X86_ALIGNMENT_16 are mutually exclusive as found
in Kconfig.cpu so it should be fine to test them separately.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

include/asm-x86/linkage.h

@@ -1,5 +1,20 @@
+#ifndef __ASM_LINKAGE_H
+#define __ASM_LINKAGE_H
+
+#ifdef CONFIG_X86_64
+#define __ALIGN .p2align 4,,15
+#define __ALIGN_STR ".p2align 4,,15"
+#endif
+
 #ifdef CONFIG_X86_32
-# include "linkage_32.h"
-#else
-# include "linkage_64.h"
+#define asmlinkage CPP_ASMLINKAGE __attribute__((regparm(0)))
+#define prevent_tail_call(ret) __asm__ ("" : "=r" (ret) : "0" (ret))
+#endif
+
+#ifdef CONFIG_X86_ALIGNMENT_16
+#define __ALIGN .align 16,0x90
+#define __ALIGN_STR ".align 16,0x90"
+#endif
+
 #endif
+