firmware: cs_dsp: Store control length as 32-bit

firmware: cs_dsp: Store control length as 32-bit

The architectures supported by this driver have a maximum of 32-bits
of address, so we don't need more than 32-bits to store the length of
control data. Change the length in struct cs_dsp_coeff_ctl to an
unsigned int instead of a size_t. Also make a corresponding trivial
change to wm_adsp.c to prevent a compiler warning.

Tested on x86_64 builds this saves at least 4 bytes per control
(another 4 bytes might be saved if the compiler was inserting padding
to align the size_t).

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20251124171536.78962-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>