arm64: dts: zte: clean up gic-v3 redistributor properties

The gic-v3 property redistributor-stride is only meant as a workaround
for broken platforms that have a redistributor stride deviating what the
architecture defines, i.e. 128KiB for GICv3, 256KiB for GICv4.  This is
not the case for ZX296718, and redistributor-stride is not really
necessary.  Let's drop it.

Also, #redistributor-regions is only required when there is more than
one such region is present.  Let's remove it as well.

Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Olof Johansson <olof@lixom.net>