arm64: dts: imx8mn: align name for crypto child nodes

crypto child nodes should use the "jr" name (without an index),
as indicated in the DT binding.

Signed-off-by: Silvano di Ninno <silvano.dininno@nxp.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>