drm/pl111: Add handling of Versatile platforms

The ARM reference designs in the Versatile family: Integrator,
Versatile and RealView can make use of the new DRM driver as well.
We just need to create a bit of platform-specific code for them
that we isolate to its own file.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20170908124709.4758-7-linus.walleij@linaro.org

drivers/gpu/drm/pl111/pl111_display.c

@@ -450,13 +450,6 @@ int pl111_display_init(struct drm_device *drm)
 	}
 	of_node_put(endpoint);
 
-	if (tft_r0b0g0[0] != 0 ||
-	    tft_r0b0g0[1] != 8 ||
-	    tft_r0b0g0[2] != 16) {
-		dev_err(dev, "arm,pl11x,tft-r0g0b0-pads != [0,8,16] not yet supported\n");
-		return -EINVAL;
-	}
-
 	ret = pl111_init_clock_divider(drm);
 	if (ret)
 		return ret;