firmware: cs_dsp: Use kvzalloc() to allocate control caches

firmware: cs_dsp: Use kvzalloc() to allocate control caches

Use kvzalloc() instead of kzalloc() to allocate memory to cache the
content of a firmware control.

Most firmware controls are only small, typically a few bytes. But on
some firmware there can be much larger controls for coefficient or
model data.

The overhead of kvzalloc() is negligible because most control allocs
can be satisfied by the normal kmalloc() that kvzalloc() will try first.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20251127103947.1094934-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>