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 <tzimmermann@suse.de>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230111130206.29974-6-tzimmermann@suse.de

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

@@ -7,7 +7,6 @@
 #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

@@ -43,7 +43,6 @@
 
 #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

@@ -11,7 +11,6 @@
 #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>