* changes:
refactor(plat/nvidia): use SOC_ID defines
refactor(plat/mediatek): use SOC_ID defines
refactor(plat/arm): use SOC_ID defines
feat(plat/st): implement platform functions for SMCCC_ARCH_SOC_ID
refactor(plat/st): export functions to get SoC information
feat(smccc): add bit definition for SMCCC_ARCH_SOC_ID