arm64: dts: lx2160a: add DT node for all DSPI controller

Add device tree node for first flash (CS0) connected
to all dspi controller.

Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
Signed-off-by: Wasim Khan <wasim.khan@nxp.com>
Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>