drm/msm/dp: remove duplicate include statement

linux/rational.h is included more than once, Remove the one that isn't
necessary.
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dp/dp_catalog.c

@@ -5,7 +5,6 @@
 
 #define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__
 
-#include <linux/rational.h>
 #include <linux/delay.h>
 #include <linux/iopoll.h>
 #include <linux/phy/phy.h>