arm64: dts: imx8mm-venice-gw7901: Remove unnecessary #address-cells/#size-cells

The following dtc build warning is seen with W=1:

arch/arm64/boot/dts/freescale/imx8mm-venice-gw7901.dts:291.14-397.4: Warning (avoid_unnecessary_addr_size): /soc@0/bus@30800000/i2c@30a20000/gsc@20: unnecessary #address-cells/#size-cells without "ranges" or child "reg" property

Remove the unnecessary #address-cells/#size-cells to fix it.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>