ASoC: sun4i-i2s: Replace call to params_width by local variable

The sun4i_i2s_hw_params function already has a variable holding the value
returned by params_width, so let's just use that variable instead of
calling params_width multiple times.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://lore.kernel.org/r/f85a1c1e014080a4bbc3abd19bc8fdcb86f0981a.1566392800.git-series.maxime.ripard@bootlin.com


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