thermal: hisilicon: Handle return value of clk_prepare_enable

commit 919054fdfc8adf58c5512fe9872eb53ea0f5525d upstream.

clk_prepare_enable() can fail here and we must check its return value.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>