media: atomisp: make const arrays static, makes object smaller

Don't populate const arrays on the stack but instead make them
static. Makes the object code smaller by 150 bytes.

Before:
   text	   data	    bss	    dec	    hex	filename
 111083	  23692	     64	 134839	  20eb7	atomisp/pci/atomisp_compat_css20.o

After:
   text	   data	    bss	    dec	    hex	filename
 110773	  23852	     64	 134689	  20e21	atomisp/pci/atomisp_compat_css20.o

After:

(gcc version 9.3.0, amd64)

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>