drm/sti: fix opencoded use of drm_panel_*

Use the drm_panel_(enable|disable|get_modes) functions.

Signed-off-by: Sam Ravnborg <[e-mail]>
Cc: Benjamin Gaignard <[e-mail]>
Cc: Vincent Abriou <[e-mail]>
Signed-off-by: Benjamin Gaignard <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/sti/sti_dvo.c

···
 
 	writel(0x00000000, dvo->regs + DVO_DOF_CFG);
 
-	if (dvo->panel)
-		dvo->panel->funcs->disable(dvo->panel);
+	drm_panel_disable(dvo->panel);
 
 	/* Disable/unprepare dvo clock */
 	clk_disable_unprepare(dvo->clk_pix);
···
 	if (clk_prepare_enable(dvo->clk))
 		DRM_ERROR("Failed to prepare/enable dvo clk\n");
 
-	if (dvo->panel)
-		dvo->panel->funcs->enable(dvo->panel);
+	drm_panel_enable(dvo->panel);
 
 	/* Set LUT */
 	writel(config->lowbyte,  dvo->regs + DVO_LUT_PROG_LOW);
···
 	struct sti_dvo *dvo = dvo_connector->dvo;
 
 	if (dvo->panel)
-		return dvo->panel->funcs->get_modes(dvo->panel);
+		return drm_panel_get_modes(dvo->panel);
 
 	return 0;
 }