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>

rockchip: px30: support px30 ...

px30 is a Quad-core soc and Cortex-a53 inside.
This patch supports the following functions:
1. basic platform setup
2. power up/off cpus
3. suspend/resume cpus
4. suspend/resume system
5. reset system
6. power off system

Change-Id: I73d55aa978096c078242be921abe0ddca9e8f67e
Signed-off-by: XiaoDong Huang <derrick.huang@rock-chips.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>

rockchip: document platform ...

This adds a rockchip.rst to docs/plat documenting the general
approach to using the Rockchip ATF platforms together with the
supported bootloaders and also adds myself as maintainer after
making sure Tony Xie is ok with that.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Change-Id: Idce53d15eff4ac6de05bbb35d86e57ed50d0cbb9