allow driver specific driver data in tas2781-hda-i2c and tas2781-i2c

Fixes: ef3bcde7 ("ASoC: tas2781: Add tas2781 driver")
CC: stable@vger.kernel.org
Signed-off-by: Gergo Koteles <soyer@irl.hu>
Link: https://lore.kernel.org/r/1398bd8bf3e935b1595a99128320e4a1913e210a.1703204848.git.soyer@irl.huSigned-off-by: Takashi Iwai <tiwai@suse.de>