ASoC: wm_adsp: Use vmemdup_user() instead of open-coding

Use vmemdup_user() to get a copy of the user buffer in wm_coeff_tlv_put().

Apart from simplifying the code and avoiding open-coding, it means we
also automatically benefit from any security enhancements in the code
behind vmemdup_user().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20250410101812.1180539-1-rf@opensource.cirrus.com


Signed-off-by: Mark Brown <broonie@kernel.org>