MIPS: Xway: Fix clk leak

When gptu_r32 fails, we should put clk before returning.

Signed-off-by: Libo Chen <libo.chen@huawei.com>
Acked-by: John Crispin <blogic@openwrt.org>
Cc: grant.likely@linaro.org
Cc: rob.herring@calxeda.com,
Cc: linux-mips@linux-mips.org
Cc: LKML linux-kernel@vger.kernel.org
Cc: Andrew Morton akpm@linux-foundation.org
Cc: Li Zefan lizefan@huawei.com
Patchwork: https://patchwork.linux-mips.org/patch/5247/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>