Various improvements/cleanups on the linker scripts ...

- Check at link-time that bootloader images will fit in memory
    at run time and that they won't overlap each other.
  - Remove text and rodata orphan sections.
  - Define new linker symbols to remove the need for platform setup
    code to know the order of sections.
  - Reduce the size of the raw binary images by cutting some sections
    out of the disk image and allocating them at load time, whenever
    possible.
  - Rework alignment constraints on sections.
  - Remove unused linker symbols.
  - Homogenize linker symbols names across all BLs.
  - Add some comments in the linker scripts.

Change-Id: I47a328af0ccc7c8ab47fcc0dc6e7dd26160610b9

fvp: Remove call to bl2_get_ns_mem_layout() function ...

On FVP platforms, for now it is assumed that the normal-world
bootloader is already sitting in its final memory location.
Therefore, BL2 doesn't need to load it and so it doesn't need
to know the extents of the non-trusted DRAM.

Change-Id: I33177ab43ca242edc8958f2fa8d994e7cf3e0843

AArch64: Remove EL-agnostic TLB helper functions ...

Also, don't invalidate the TLBs in disable_mmu() function, it's better
to do it in enable_mmu() function just before actually enabling the
MMU.

Change-Id: Ib32d6660019b0b2c17254156aad4be67ab4970e1

fvp: Remove unnecessary initializers ...

Global and static variables are expected to be initialised to zero
by default.  This is specified by the C99 standard. This patch
removes some unnecessary initialisations of such variables.

It fixes a compilation warning at the same time:
  plat/fvp/bl31_plat_setup.c:82:3: warning: missing braces around
  initializer [-Wmissing-braces]
     section("tzfw_coherent_mem"))) = {0};
     ^
  plat/fvp/bl31_plat_setup.c:82:3: warning: (near initialization for
  ‘ns_entry_info[0]’) [-Wmissing-braces]

Note that GCC should not have emitted this warning message in the
first place.  The C Standard permits braces to be elided around
subaggregate initializers.  See this GCC bug report:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119

Change-Id: I13cb0c344feb9803bca8819f976377741fa6bc35

Move generic architectural setup out of blx_plat_arch_setup(). ...

blx_plat_arch_setup() should only perform platform-specific
architectural setup, e.g. enabling the MMU.  This patch moves
generic architectural setup code out of blx_plat_arch_setup().

Change-Id: I4ccf56b8c4a2fa84909817779a2d97a14aaafab6

Do not enable CCI on Foundation FVP ...

- The Foundation FVP only has one cluster and does not have
  CCI.

Change-Id: If91e81ff72c52e448150089c4cfea3e4d6ae1232

Writing to the FVP LED register should be a 32bit access. ...

- Writing to this register with a 64bit access can cause a
  Systen Error Exception on some models.

Change-Id: Ibcf5bdf7ab55707db61c16298f25caff50e1ff7e

ARMv8 Trusted Firmware release v0.2