boards: amlogic: Add FriendlyElec NanoPi K2 board support

This adds platform code for the FriendlyElec NanoPi K2 board based on a
Meson GXBB (S905) SoC with the Meson GXBB configuration.

This initial submission only supports:
- UART
- MMC/SDCard
- Ethernet
- Reset Controller
- Clock controller

Cc: Yuefei Tan <yftan@friendlyarm.com>
Signed-off-by: Thomas McKahan <tonymckahan@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
9 files changed