arm64: add __ASSEMBLY__ in asm/insn.h

Since insn.h is indirectly included in asm/entry-ftrace.S,
we need to exclude some declarations by __ASSEMBLY__.

Acked-by: Will Deacon <[e-mail]>
Signed-off-by: AKASHI Takahiro <[e-mail]>
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/include/asm/insn.h

···
 /* A64 instructions are always 32 bits. */
 #define	AARCH64_INSN_SIZE		4
 
+#ifndef __ASSEMBLY__
 /*
  * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
  * Section C3.1 "A64 instruction index by encoding":
···
 int aarch64_insn_patch_text_nosync(void *addr, u32 insn);
 int aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt);
 int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt);
+#endif /* __ASSEMBLY__ */
 
 #endif	/* __ASM_INSN_H */