There is no necessity to pass an endpoint device node to custom panel
initialization functions, because a child panel device node should be
sufficient, note that the existing init_panel() callback declaration from
linux/amba/clcd.h already prompts to use the panel device node here.

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

This adds a special panel init hook for the ARM reference designs
Integrator (IM-PD1), Versatile and RealView, so we can configure
a DPI panel from device tree and have it working without
boardfiles for these machines.

Basically this is the same code as from the board files, just
moved over to look up the syscon DT node and manipulate the
special CLCD register from their regmap.

Tested on RealView PB11MPcore.

Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>