ASoC: rt1305: make array pd static const, makes object smaller

Don't populate the array pd on the stack but instead make it
static const. Makes the object code smaller by 93 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
  38961	   9784	     64	  48809	   bea9	sound/soc/codecs/rt1305.o

After:
   text	   data	    bss	    dec	    hex	filename
  38804	   9848	     64	  48716	   be4c	sound/soc/codecs/rt1305.o

(gcc version 9.2.1, amd64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20190907074156.21907-1-colin.king@canonical.com


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