Add them to the SoC .dtsi, so that not every board has to specify them.

Fixes: 1225396f ("arm64: dts: imx93: add lpi2c nodes")
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>