drm/panel: Do not include <linux/fb.h>

Remove unnecessary include statements for <linux/fb.h>. No functional
changes. Include <linux/of.h> where the driver got the header file via
<linux/fb.h>.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Acked-by: Maxime Ripard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/panel/panel-ilitek-ili9881c.c

···
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/errno.h>
-#include <linux/fb.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_device.h>

drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c

···
 
 #include <linux/delay.h>
 #include <linux/err.h>
-#include <linux/fb.h>
 #include <linux/i2c.h>
 #include <linux/media-bus-format.h>
 #include <linux/module.h>

drivers/gpu/drm/panel/panel-ronbo-rb070d30.c

···
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/errno.h>
-#include <linux/fb.h>
 #include <linux/kernel.h>
 #include <linux/media-bus-format.h>
 #include <linux/module.h>