ARM: dts: imx7s: Pass the 'fsl,sec-era' property

Currently the following error is seen from the CAAM driver:

caam 30900000.caam: device ID = 0x0a16030000000000 (Era -524)

Pass the 'fsl,sec-era' property to properly describe the
era information.

This error happens because the 'fsl,sec-era' is not passed via
device tree.

The era information is used in various places inside drivers/crypto/caam,
so pass the correct version via device tree.

Fixes: 0eeabcad ("ARM: dts: imx7s: add CAAM device node")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>