intel: Change boot source selection

Platform handoff structure no longer includes boot source selection.
Hence, those settings can now be configured through socfpga_plat_def.h.

Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: If7ec6a03bb25156a6670ebf8f77105c370b553f6
5 files changed