Fix MISRA rule 8.4 in common code ...

Rule 8.4: A compatible declaration shall be visible when
          an object or function with external linkage is defined.

Change-Id: I26e042cb251a6f9590afa1340fdac73e42f23979
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

bl2-el3: Add BL2_EL3 image ...

This patch enables BL2 to execute at the highest exception level
without any dependancy on TF BL1. This enables platforms which already
have a non-TF Boot ROM to directly load and execute BL2 and subsequent BL
stages without need for BL1.  This is not currently possible because
BL2 executes at S-EL1 and cannot jump straight to EL3.

Change-Id: Ief1efca4598560b1b8c8e61fbe26d1f44e929d69
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

Changes for new version of image loading in BL1/BL2 ...

This patch adds changes in BL1 & BL2 to use new version
of image loading to load the BL images.

Following are the changes in BL1:
  -Use new version of load_auth_image() to load BL2
  -Modified `bl1_init_bl2_mem_layout()` to remove using
   `reserve_mem()` and to calculate `bl2_mem_layout`.
   `bl2_mem_layout` calculation now assumes that BL1 RW
   data is at the top of the bl1_mem_layout, which is more
   restrictive than the previous BL1 behaviour.

Following are the changes in BL2:
  -The `bl2_main.c` is refactored and all the functions
   for loading BLxx images are now moved to `bl2_image_load.c`
   `bl2_main.c` now calls a top level `bl2_load_images()` to
   load all the images that are applicable in BL2.
  -Added new file `bl2_image_load_v2.c` that uses new version
   of image loading to load the BL images in BL2.

All the above changes are conditionally compiled using the
`LOAD_IMAGE_V2` flag.

Change-Id: Ic6dcde5a484495bdc05526d9121c59fa50c1bf23

Remove extern keyword from function declarations ...

Function declarations implicitly have external linkage so do not
need the extern keyword.

Change-Id: Ia0549786796d8bf5956487e8996450a0b3d79f32

Separate BL functions out of arch.h ...

Move the BL function prototypes out of arch.h and into the
appropriate header files to allow more efficient header file
inclusion. Create new BL private header files where there is no
sensible existing header file.

Change-Id: I45f3e10b72b5d835254a6f25a5e47cf4cfb274c3