drm/ttm: Include <linux/export.h>

drm/ttm: Include <linux/export.h>

Fix the compile-time warnings

  drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/tests/ttm_mock_manager.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_agp_backend.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_backup.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_bo.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_bo_util.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_bo_vm.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_device.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_execbuf_util.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_pool.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_range_manager.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_resource.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing
  drivers/gpu/drm/ttm/ttm_tt.c: warning: EXPORT_SYMBOL() is used, but #include <linux/export.h> is missing

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: a934a57a42f6 ("scripts/misc-check: check missing #include <linux/export.h> when W=1")
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20250612121633.229222-10-tzimmermann@suse.de