drm/tegra: sor: Disable clocks on error in tegra_sor_init()

Fix the missing clk_disable_unprepare() before return from
tegra_sor_init() in the error handling case.

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>