Prepares for the addition of the IOT2050 board which is based on the TI
AM65x. The board comes in four variants, Basic and Advanced, each as
product generation 1 (SR1.0) and 2 (SR2.x), so there are separate dts
files needed. Furthermore, the SPL has its own device tree.
Based on original board support by Le Jin, Gao Nian and Chao Zeng.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>