amlogic: axg: Add a build flag when using ATOS as BL32 ...

BL2 is unconditionally setting 0 (OPTEE_AARCH64) in arg0 even when the
BL32 image is 32bit (OPTEE_AARCH32). This is causing the boot to hang
when ATOS (32bit Amlogic BL32 binary-only TEE OS) is used.

Since we are not aware of any Amlogic platform shipping a 64bit version
of ATOS we can hardcode OPTEE_AARCH32 / MODE_RW_32 when using ATOS.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Change-Id: Iaea47cf6dc48bf8a646056761f02fb81b41c78a3

amlogic: axg: Add support for the A113D (AXG) platform ...

Introduce the preliminary support for the Amlogic A113D (AXG) SoC.

This port is a minimal implementation of BL31 capable of booting
mainline U-Boot, Linux and chainloading BL32 (ATOS).

Tested on a A113D board.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Change-Id: Ic4548fa2f7c48d61b485b2a6517ec36c53c20809