MLK-21823-2 arm64: dts: freescale: add i.MX8MN DT files

MLK-21823-2 arm64: dts: freescale: add i.MX8MN DT files

Add new SoC i.MX8MN's DT files and support it by default.

Signed-off-by: Bai Ping <ping.bai@nxp.com>
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Ella Feng <ella.feng@nxp.com>
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Teo Hall <teo.hall@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Viorel Suman <viorel.suman@nxp.com>
Signed-off-by: Cosmin-Gabriel Samoila <cosmin.samoila@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Bai Ping <ping.bai@nxp.com>