feat(s32g274a): enable BL31 stage

Add BL31 prerequisites for the S32G274ARDB2 board to allow single-core
cold boot without MMU and PSCI services.

Change-Id: I8a10fd62f3cc9430083758043ea82e3803f61060
Signed-off-by: Bogdan Hamciuc <bogdan.hamciuc@nxp.com>
Signed-off-by: Bogdan Roman <bogdan-gabriel.roman@nxp.com>
Signed-off-by: Andra-Teodora Ilie <andra.ilie@nxp.com>
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>