Add the i.MX91 device tree from [1]. These files could be synced
to linux upstream after [1] merged to linux source tree.
[1]
https://lore.kernel.org/all/20241120094945.3032663-1-pengfei.li_1@nxp.com/
Signed-off-by: Peng Fan <peng.fan@nxp.com>
(cherry picked from commit c4ee9df4a4)