riscv: traps_misaligned: do not duplicate stringify

Use existing stringify macro from the kernel headers.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20220623112905.253157-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>