drm/i915: include some drm headers only where needed

Include drm_fourcc.h, drm_plane.h, and drm_color_mgmt.h where needed, so
we can drop the includes for drm_atomic.h and drm_fourcc.h from
i915_drv.h, reducing the build dependencies.

Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b03711b2286396b2e9d5822f6adef4e7a6dc0f7b.1644507885.git.jani.nikula@intel.com

drivers/gpu/drm/i915/gem/i915_gem_create.c

@@ -3,6 +3,8 @@
  * Copyright © 2020 Intel Corporation
  */
 
+#include <drm/drm_fourcc.h>
+
 #include "gem/i915_gem_ioctls.h"
 #include "gem/i915_gem_lmem.h"
 #include "gem/i915_gem_region.h"

drivers/gpu/drm/i915/gvt/dmabuf.c

@@ -31,6 +31,9 @@
 #include <linux/dma-buf.h>
 #include <linux/vfio.h>
 
+#include <drm/drm_fourcc.h>
+#include <drm/drm_plane.h>
+
 #include "gem/i915_gem_dmabuf.h"
 
 #include "i915_drv.h"

drivers/gpu/drm/i915/i915_drv.h

@@ -31,7 +31,6 @@
 #define _I915_DRV_H_
 
 #include <uapi/drm/i915_drm.h>
-#include <uapi/drm/drm_fourcc.h>
 
 #include <asm/hypervisor.h>
 
@@ -52,7 +51,6 @@
 #include <drm/drm_auth.h>
 #include <drm/drm_util.h>
 #include <drm/drm_dsc.h>
-#include <drm/drm_atomic.h>
 #include <drm/drm_connector.h>
 #include <drm/i915_mei_hdcp_interface.h>
 #include <drm/ttm/ttm_device.h>

drivers/gpu/drm/i915/i915_pci.c

@@ -22,6 +22,7 @@
  *
  */
 
+#include <drm/drm_color_mgmt.h>
 #include <drm/drm_drv.h>
 #include <drm/i915_pciids.h>