drm: Remove unnecessary include statements for drm_crtc_helper.h

Several DRM core and helper source files include drm_crtc_helper.h
without needing it or only to get its transitive include statements;
leading to unnecessary compile-time dependencies.

Directly include required headers and drop drm_crtc_helper.h where
possible. The header file, drm_fixed.h, includes <linux/kernel.h>
for lower_32_bits().

v2:
	* include drm_crtc_helper.h in drm_crtc_helper.c (Sam)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230116131235.18917-3-tzimmermann@suse.de

drivers/gpu/drm/drm_lease.c

@@ -6,7 +6,7 @@
 #include <linux/uaccess.h>
 
 #include <drm/drm_auth.h>
-#include <drm/drm_crtc_helper.h>
+#include <drm/drm_crtc.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_lease.h>

drivers/gpu/drm/drm_plane_helper.c

@@ -28,7 +28,6 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_atomic_uapi.h>
-#include <drm/drm_crtc_helper.h>
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_encoder.h>

include/drm/drm_fixed.h

@@ -25,6 +25,7 @@
 #ifndef DRM_FIXED_H
 #define DRM_FIXED_H
 
+#include <linux/kernel.h>
 #include <linux/math64.h>
 
 typedef union dfixed {