drm: Replace kernel.h with the necessary inclusions

When kernel.h is used in the headers it adds a lot into dependency hell,
especially when there are circular dependencies are involved.

Replace kernel.h inclusion with the list of what is really being used.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20211110102423.54282-1-andriy.shevchenko@linux.intel.com

include/drm/drm_gem_ttm_helper.h

@@ -3,7 +3,7 @@
 #ifndef DRM_GEM_TTM_HELPER_H
 #define DRM_GEM_TTM_HELPER_H
 
-#include <linux/kernel.h>
+#include <linux/container_of.h>
 
 #include <drm/drm_device.h>
 #include <drm/drm_gem.h>

include/drm/drm_gem_vram_helper.h

@@ -11,8 +11,8 @@
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
+#include <linux/container_of.h>
 #include <linux/dma-buf-map.h>
-#include <linux/kernel.h> /* for container_of() */
 
 struct drm_mode_create_dumb;
 struct drm_plane;

include/drm/drm_mm.h

@@ -39,13 +39,15 @@
  */
 #include <linux/bug.h>
 #include <linux/rbtree.h>
-#include <linux/kernel.h>
+#include <linux/limits.h>
 #include <linux/mm_types.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #ifdef CONFIG_DRM_DEBUG_MM
 #include <linux/stackdepot.h>
 #endif
+#include <linux/types.h>
+
 #include <drm/drm_print.h>
 
 #ifdef CONFIG_DRM_DEBUG_MM