[media] gspca: make arrays static, reduces object code size

Don't populate const arrays on the stack, instead make them
static.  Makes the object code smaller by over 5200 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  58259	   8880	    128	  67267	  106c3	ov519.o

After:
   text	   data	    bss	    dec	    hex	filename
  52155	   9776	    128	  62059	   f26b	ov519.o

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>