ASoC: s3c24xx_uda134x: Move global variables to driver's data structure

Gather all driver's private variables in common data structure
and allocate the data structure dynamically.

Also unused ENFORCE_RATES symbol and local variable (leftovers
from an erroneous rebase) are removed.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>