drm: fb: Add seq_file definition

Otherwise, building with DEBUG_FS enabled will trigger a build warning
because we're using a structure that has not been declared.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
This commit is contained in:
Maxime Ripard 2016-02-08 13:58:56 +01:00
commit 80588a86af