Lib: Add to dai-legacy.h struct copier_gain_params for testbench#9536

kv2019i merged 2 commits intothesofproject:mainthesofproject/sof:mainfrom

singalsu:copier_gain_fix_testbench_ipc4_buildsingalsu/sof:copier_gain_fix_testbench_ipc4_buildCopy head branch name to clipboard