ASoC: samsung: i2s: samsung_i2s_get_driver_data() cleanup

Tidy up the samsung_i2s_get_driver_data() function by using
IS_ENABLE() instead of #ifdef and add missing braces for
the 'else' part. Also ensure we are not dereferencing NULL
'match' pointer.

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