drm/pl111: Support Nomadik LCDC variant

The Nomadik has a variant of the PL110 known as "Color LCD
Controller" LCDC. This variant has the same bit ordering as
the DRM subsystem (in difference from the other variants)
and adds a few bits for the control of 5551, 565 etc in the
control register. Notably it also adds a packed RGB888
24BPP mode.

We add support by detecting this variant and also adding a
small plug-in that will mux the LCDC out if the ASIC happens
to be muxed to the other graphics controller (they are
mutually exclusive).

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180621184450.25377-1-linus.walleij@linaro.org

drivers/gpu/drm/pl111/pl111_nomadik.h

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/device.h>
+
+#ifndef PL111_NOMADIK_H
+#define PL111_NOMADIK_H
+#endif
+
+#ifdef CONFIG_ARCH_NOMADIK
+
+void pl111_nomadik_init(struct device *dev);
+
+#else
+
+static inline void pl111_nomadik_init(struct device *dev)
+{
+}
+
+#endif