ASoC: fsl: constify static snd_soc_dai_ops structs

The only usage of these is to assign their address to the 'ops' field in
the snd_soc_dai_driver struct, which is a pointer to const. Make them
const to allow the compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Link: https://lore.kernel.org/r/20210206225849.51071-1-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>