imx8: Configure SNVS

imx8: Configure SNVS

Add a module to configure the tamper and secure violation of
the SNVS using the SCU API.

The module also adds some commands:
 - snvs_cfg: Configure the SNVS HP and LP registers
 - snvs_dgo_cfg: Configure the SNVS DGO bloc if present (8QXP)
 - tamper_pin_cfg: Change the configuration of the tamper pins
 - snvs_clear_status: Allow to write to LPSR and LPTDSR to clear
   status bits

Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>