Initialize platform for MediaTek MT8195

- Add basic platform setup
- Add MT8195 documentation at docs/plat/
- Add generic CPU helper functions
- Add basic register address

Change-Id: I7978e2f32e58900e5cf93f741ee8eaf8b8e3b842
diff --git a/docs/plat/index.rst b/docs/plat/index.rst
index 3cbb552..06c5c2b 100644
--- a/docs/plat/index.rst
+++ b/docs/plat/index.rst
@@ -20,6 +20,7 @@
    marvell/index
    mt8183
    mt8192
+   mt8195
    nvidia-tegra
    warp7
    imx8