x86: Make simd.h more resilient

Add missing header inclusions and protect against double inclusion.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/include/asm/simd.h

@@ -1,6 +1,10 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_SIMD_H
+#define _ASM_SIMD_H
 
 #include <asm/fpu/api.h>
+#include <linux/compiler_attributes.h>
+#include <linux/types.h>
 
 /*
  * may_use_simd - whether it is allowable at this time to issue SIMD
@@ -10,3 +14,5 @@ static __must_check inline bool may_use_simd(void)
 {
 	return irq_fpu_usable();
 }
+
+#endif	/* _ASM_SIMD_H */