arm64: dts: renesas: r8a77995: draak: Remove bogus adv7511w properties

The "max-clock" and "min-vrefresh" properties fail to validate with
commit cfe34bb7 ("dt-bindings: drm: bridge: adi,adv7511.txt:
convert to yaml").  Drop them, as they are parts of an out-of-tree
workaround that is not needed upstream.

Fixes: bcf30034 ("arm64: dts: renesas: r8a77995: draak: Enable HDMI display output")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/975b6686bc423421b147d367fe7fb9a0db99c5af.1625134398.git.geert+renesas@glider.be