clk: mediatek: clk-mt8173-apmixedsys: Use common error handling code in clk_mt8173_apmixed_probe()

Add a label so that a bit of exception handling can be better reused
at the end of this function implementation.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Link: https://lore.kernel.org/r/6a64e7b3-b1ce-46c4-9c85-89f731aee592@web.de


Reviewed-by: AngeloGiaocchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>