ASoC: sti: use managed regmap_field allocations

ASoC: sti: use managed regmap_field allocations

The regmap_field objects allocated at player init are never freed and
may leak resources if the driver is removed.

Switch to devm_regmap_field_alloc() to automatically limit the lifetime
of the allocations the lifetime of the device.

Fixes: 76c2145ded6b ("ASoC: sti: Add CPU DAI driver for playback")
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Link: https://patch.msgid.link/20260220152634.480766-3-sander@svanheule.net
Signed-off-by: Mark Brown <broonie@kernel.org>