Use devm_clk_get_optional() instead of hand writing it.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/51976b2515d7007ba5c8aa7524892f147d7cdd51.1681363691.git.christophe.jaillet@wanadoo.frSigned-off-by: Mark Brown <broonie@kernel.org>