ASoC: SDCA: Add stubs for FDL helper functions

ASoC: SDCA: Add stubs for FDL helper functions

In the case the SDCA IRQ is built in but FDL support is not stub
functions are required for the FDL helpers to avoid build failures. The
FDL IRQs likely shouldn't get triggered in this case, however they would
still be a part of the build.

Fixes: 71f7990a34cd ("ASoC: SDCA: Add FDL library for XU entities")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511200419.SbU6YvjE-lkp@intel.com/
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20251120155657.2181751-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>