Revert "GCC: Upgrade to version 9.2-2019.12 of toolchain" ...

This reverts commit de9bf1d.

Change-Id: Iebb6297ce290a10ee850bf6a9c71e7eb530b085f

GCC: Upgrade to version 9.2-2019.12 of toolchain ...

This toolchain provides multiple cross compilers and are publicly
available on www.developer.arm.com

We thoroughly test TF-A in CI using:
AArch32 bare-metal target (arm-none-eabi)
AArch64 ELF bare-metal target (aarch64-none-elf)

Change-Id: I2360a3ac6705c68dca781b85e9894867df255b3e
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

doc: Reformat platform port documents ...

The platform port documents are not very standardised right now and
they don't integrate properly into the document tree so:

1) Make sure each port has a proper name and title (incl. owner)
2) Correct use of headings, subheadings, etc in each port
3) Resolve any naming conflicts between documents

Change-Id: I4c2da6f57172b7f2af3512e766ae9ce3b840b50f
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

ti: k3: Setup initial files for platform ...

Create the baseline Makefile, platform definitions file and platform
specific assembly macros file. This includes first set of constants
for the platform including cache sizes and linker format and a stub for
BL31 and the basic memory layout

K3 SoC family of processors do not use require a BL1 or BL2 binary,
since such functions are provided by an system controller on the SoC.
This lowers the burden of ATF to purely managing the local ARM cores
themselves.

Signed-off-by: Benjamin Fair <b-fair@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>