ASoC: rsnd: make some arrays static const, makes object smaller

Don't populate arrays on the stack but instead them static const.
Makes the object code smaller by 242 bytes.

Before:
   text    data     bss     dec     hex filename
  23827    8764       0   32591    7f4f ./sound/soc/sh/rcar/ssi.o

After:
   text    data     bss     dec     hex filename
  23361    8988       0   32349    7e5d ./sound/soc/sh/rcar/ssi.o

gcc version 10.2.0)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210801063237.137998-1-colin.king@canonical.com


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