This adds BL31 support to Intel Stratix10 SoCFPGA platform. BL31 in TF-A
supports:
- PSCI calls to enable 4 CPU cores
- PSCI mailbox calls for FPGA reconfiguration

Signed-off-by: Loh Tien Hock <tien.hock.loh@intel.com>

A DDR calibration value is missing write mask, causing ECC DDR calibration
to fail. This patch addresses the issue. ECC should also be scrubbed before
MMU initializes, thus the scrubbing is moved to ddr intialization phase.

Signed-off-by: Loh Tien Hock <tien.hock.loh@intel.com>

This adds BL2 support for Intel Stratix 10 SoC FPGA.
Functionality includes:
- Release and setup peripherals from reset
- Calibrate DDR
- ECC DDR Scrubbing
- Load FIP (bl31 and bl33)

Signed-off-by: Loh Tien Hock <tien.hock.loh@intel.com>