drm/exynos: Remove useless slab.h include

Signed-off-by: NStephane Marchesin <marcheu@chromium.org>
Signed-off-by: NSean Paul <seanpaul@chromium.org>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/video/exynos/exynos_dp_core.c

@@ -12,7 +12,6 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>