ASoC: tas2781: Fix the wrong step for TLV on tas2781

The step for TLV on tas2781, should be 50 (-0.5dB).

Fixes: 678f38eb ("ASoC: tas2781: Add Header file for tas2781 driver")
Signed-off-by: Baojun Xu <baojun.xu@ti.com>
Link: https://patch.msgid.link/20250801021618.64627-1-baojun.xu@ti.com


Signed-off-by: Mark Brown <broonie@kernel.org>