video: fbdev: vt8623fb: constify vt8623_timing_regs

vt8623_timing_regs is only passed as the first argument to
svga_check_timings and as the second argument to svga_set_timings,
both of which are const.  So make vt8623_timing_regs const also.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/video/fbdev/vt8623fb.c

@@ -81,7 +81,7 @@ static struct vga_regset vt8623_line_compare_regs[]  = {{0x18, 0, 7}, {0x07, 4,
 static struct vga_regset vt8623_fetch_count_regs[]   = {{0x1C, 0, 7}, {0x1D, 0, 1}, VGA_REGSET_END};
 static struct vga_regset vt8623_start_address_regs[] = {{0x0d, 0, 7}, {0x0c, 0, 7}, {0x34, 0, 7}, {0x48, 0, 1}, VGA_REGSET_END};
 
-static struct svga_timing_regs vt8623_timing_regs     = {
+static const struct svga_timing_regs vt8623_timing_regs     = {
 	vt8623_h_total_regs, vt8623_h_display_regs, vt8623_h_blank_start_regs,
 	vt8623_h_blank_end_regs, vt8623_h_sync_start_regs, vt8623_h_sync_end_regs,
 	vt8623_v_total_regs, vt8623_v_display_regs, vt8623_v_blank_start_regs,