feat(mt8196): initialize platform for MediaTek MT8196

- Add basic platform setup.
- Add MT8196 documentation at docs/plat/.
- Add generic CPU helper functions.
- Add basic register address.
- Add timer driver configuration.

Change-Id: I07fcdeb785fcda4a955c11c39a345da4ad05ef04
Signed-off-by: Gavin Liu <gavin.liu@mediatek.com>
diff --git a/docs/plat/index.rst b/docs/plat/index.rst
index a8e0c8d..0b53d1d 100644
--- a/docs/plat/index.rst
+++ b/docs/plat/index.rst
@@ -24,6 +24,7 @@
    mt8188
    mt8192
    mt8195
+   mt8196
    nvidia-tegra
    warp7
    imx8