video: fbdev: aty128fb: remove unused 'sdr_64'

Fix the following gcc warning:

drivers/video/fbdev/aty/aty128fb.c:337:36: warning: ‘sdr_64’ defined but
not used [-Wunused-const-variable=]
 static const struct aty128_meminfo sdr_64 = {
                                    ^~~~~~
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200417092318.13978-1-yanaijie@huawei.com

drivers/video/fbdev/aty/aty128fb.c

@@ -334,20 +334,6 @@ static const struct aty128_meminfo sdr_128 = {
 	.name = "128-bit SDR SGRAM (1:1)",
 };
 
-static const struct aty128_meminfo sdr_64 = {
-	.ML = 4,
-	.MB = 8,
-	.Trcd = 3,
-	.Trp = 3,
-	.Twr = 1,
-	.CL = 3,
-	.Tr2w = 1,
-	.LoopLatency = 17,
-	.DspOn = 46,
-	.Rloop = 17,
-	.name = "64-bit SDR SGRAM (1:1)",
-};
-
 static const struct aty128_meminfo sdr_sgram = {
 	.ML = 4,
 	.MB = 4,