fbtft: seps525: Don't use "proxy" headers

Update header inclusions to follow IWYU (Include What You Use)
principle.

Signed-off-by: Andy Shevchenko <[e-mail]>
Acked-by: Michael Hennerich <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/fbtft/fb_seps525.c

···
  * GNU General Public License for more details.
  */
 
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/gpio.h>
+#include <linux/bits.h>
 #include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/module.h>
 
 #include "fbtft.h"