drm/lcdif: Clean up headers

Drop unneeded headers, sort rest alphabetically, no functional change.

Acked-by: Sam Ravnborg <[e-mail]>
Reviewed-by: Liu Ying <[e-mail]>
Reported-by: Liu Ying <[e-mail]>
Tested-by: Martyn Welch <[e-mail]>
Fixes: 9db35bb349a0e ("drm: lcdif: Add support for i.MX8MP LCDIF variant")
Signed-off-by: Marek Vasut <[e-mail]>
Cc: Alexander Stein <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Cc: Liu Ying <[e-mail]>
Cc: Lucas Stach <[e-mail]>
Cc: Marek Vasut <[e-mail]>
Cc: Martyn Welch <[e-mail]>
Cc: Peng Fan <[e-mail]>
Cc: Robby Cai <[e-mail]>
Cc: Sam Ravnborg <[e-mail]>
Cc: Stefan Agner <[e-mail]>
Reviewed-by: Alexander Stein <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/mxsfb/lcdif_drv.c

···
 #include <linux/clk.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
-#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
···
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
-#include <drm/drm_connector.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fb_helper.h>
-#include <drm/drm_fourcc.h>
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_mode_config.h>

drivers/gpu/drm/mxsfb/lcdif_drv.h

···
 #ifndef __LCDIF_DRV_H__
 #define __LCDIF_DRV_H__
 
+#include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_device.h>
 #include <drm/drm_encoder.h>

drivers/gpu/drm/mxsfb/lcdif_kms.c

···
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_encoder.h>
-#include <drm/drm_framebuffer.h>
 #include <drm/drm_fb_dma_helper.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_atomic_helper.h>
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_plane.h>