drm/ast: Remove unnecessary include statements for drm_crtc_helper.h

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

Drop drm_crtc_helper.h where possible.

v2:
	* update commit message (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/20230116131235.18917-7-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_drv.c

@@ -31,7 +31,6 @@
 
 #include <drm/drm_aperture.h>
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_crtc_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_fbdev_generic.h>
 #include <drm/drm_gem_shmem_helper.h>

drivers/gpu/drm/ast/ast_main.c

@@ -29,7 +29,6 @@
 #include <linux/pci.h>
 
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_crtc_helper.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_managed.h>

drivers/gpu/drm/ast/ast_mode.c

@@ -35,7 +35,6 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_atomic_state_helper.h>
 #include <drm/drm_crtc.h>
-#include <drm/drm_crtc_helper.h>
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_format_helper.h>