clk: imx8mq: Unregister clks when of_clk_add_provider failed

When of_clk_add_provider failed, all clks should be unregistered.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>