MIPS: Alchemy: Fix memleak in alchemy_clk_setup_cpu

If the clk_register fails, we should free h before
function returns to prevent memleak.

Fixes: 47440229

 ("MIPS: Alchemy: clock framework integration of onchip clocks")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>