riscv: Add header include guards to insn.h

riscv: Add header include guards to insn.h

[ Upstream commit 8d67620f8f7a6074e7b71a9512ac9a079c603101 ]

Add header include guards to insn.h to prevent repeating declaration of
any identifiers in insn.h.

Fixes: 6167fe89f405 ("riscv: Add SW single-step support for KDB")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Fixes: 933ebad06cf0 ("RISC-V: rename parse_asm.h to insn.h")
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230129094242.282620-1-liaochang1@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>