ASoC: SDCA: Shrink detected_mode_handler() stack frame

ASoC: SDCA: Shrink detected_mode_handler() stack frame

The stack frame for detected_mode_handler() is a bit large. Dynamically
allocate the control value struct, which is most of the size, to avoid
this.

Fixes: b9ab3b618241 ("ASoC: SDCA: Add some initial IRQ handlers")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507182222.OLgOy9fX-lkp@intel.com/
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20250722102305.2513755-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>