drm/msm/mdp5: Remove unneeded semicolon

Fixes coccicheck warning:

drivers/gpu/drm/msm/disp/mdp5/mdp5_cfg.c:905:2-3: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>