Pull out handoff driver to intel/soc/ common directory as they can be
shared by both Agilex and Stratix10 platform.

Share platform_def header between both Agilex and Stratix10 and store
platform specific definitions in socfpga_plat_def.h

Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I8eff1afd7ee71704a36a54fad732ede4f557878d

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>