[media] easycap: compress initialization tables

1. saa and stk initialization tables are less then
256 entries
2. stk table can fit into u16 and saa into u8

size before
 text	   data	    bss	    dec	    hex	filename
 105687	   1072	1134800	1241559	 12f1d7	easycap.ko

size after

 text	   data	    bss	    dec	    hex	filename
 97919	   1072	1134800	1233791	 12d37f	easycap.ko

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>