Add generic header files support for nds32 architecture.
Cache, ptregs, data type and other definitions are included.
Signed-off-by: Macpaul Lin <macpaul@andestech.com>
This helps to clean up the include/ directory so that it only contains
non-architecture-specific headers and also matches Linux's directory
layout which many U-Boot developers are already familiar with.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>