gpu/ipu-v3/ipu-di: Strip out 2 unused 'di_sync_config' entries

They're taking up too much space on the stack.

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/ipu-v3/ipu-di.c: In function ‘ipu_di_sync_config_noninterlaced’:
 drivers/gpu/ipu-v3/ipu-di.c:391:1: warning: the frame size of 1064 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>