GitLab

  - Assign 0x10 for RAS exceptions on ARM platforms, and install
    EHF priority descriptor.

  - Call the common RAS initialisation from ARM BL31 setup.

  - Add empty definitions for platform error records and RAS interrupts.

Change-Id: I0675f299b7840be4c83a9c7a81073a95c605dc90
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>