arm64: dts: allwinner: a64: Fix display clock register range

Register range of display clocks is 0x10000, as it can be seen from
DE2 documentation.

Fix it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Fixes: 2c796fc8 ("arm64: dts: allwinner: a64: add necessary device tree nodes for DE2 CCU")
[wens@csie.org: added fixes tag]
Signed-off-by: Chen-Yu Tsai <wens@csie.org>