video: fbdev: aty: make const arrays static, reduces object code size

Don't populate the const arrays ragepro_tbl and ragexl_tbl on the stack,
instead make them static.  Makes the object code smaller by over 380 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  41089	  10592	    768	  52449	   cce1 atyfb_base.o

After:
   text	   data	    bss	    dec	    hex	filename
  40544	  10752	    768	  52064	   cb60	atyfb_base.o

(gcc version 7.2.0, x86_64)
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/aty/atyfb_base.c

@@ -2272,10 +2272,10 @@ static void aty_bl_exit(struct backlight_device *bd)
 
 static void aty_calc_mem_refresh(struct atyfb_par *par, int xclk)
 {
-	const int ragepro_tbl[] = {
+	static const int ragepro_tbl[] = {
 		44, 50, 55, 66, 75, 80, 100
 	};
-	const int ragexl_tbl[] = {
+	static const int ragexl_tbl[] = {
 		50, 66, 75, 83, 90, 95, 100, 105,
 		110, 115, 120, 125, 133, 143, 166
 	};