drm/simple-kms-helper: Plumb plane state to the enable hook

tinydrm enable hook wants to play around with the new fb in
.atomic_enable(), thus we'll need access to the plane state.

Performed with coccinelle:
@r1@
identifier F =~ ".*enable$";
identifier P, CS;
@@
F(
	struct drm_simple_display_pipe *P
	,struct drm_crtc_state *CS
+	,struct drm_plane_state *plane_state
	)
{
...
}

@@
struct drm_simple_display_pipe *P;
expression E;
@@
{
+ struct drm_plane *plane;
...
+ plane = &P->plane;
P->funcs->enable(P
		,E
+		,plane->state
	);
...
}

@@
identifier P, CS;
@@
struct drm_simple_display_pipe_funcs {
...
        void (*enable)(struct drm_simple_display_pipe *P
	     		,struct drm_crtc_state *CS
+			,struct drm_plane_state *plane_state
		);
...
};

v2: Pimp the commit message (David)

Cc: Marek Vasut <marex@denx.de>
Cc: Eric Anholt <eric@anholt.net>
Cc: David Lechner <david@lechnology.com>
Cc: "Noralf Trønnes" <noralf@tronnes.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322202738.25817-1-ville.syrjala@linux.intel.com
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>

drivers/gpu/drm/tinydrm/repaper.c

@@ -659,7 +659,8 @@ static void power_off(struct repaper_epd *epd)
 }
 
 static void repaper_pipe_enable(struct drm_simple_display_pipe *pipe,
-				struct drm_crtc_state *crtc_state)
+				struct drm_crtc_state *crtc_state,
+				struct drm_plane_state *plane_state)
 {
 	struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
 	struct repaper_epd *epd = epd_from_tinydrm(tdev);