Move the environment into the board directory and convert header to a
txt file. In addition, this patch also applies following changes:
- Change default nfsroot path to /srv/nfs due to compliance with Linux
FHS 3.0.
- Rename specific variables as stated in the bootstd documentation.
Renamed variables:
fdt_addr => fdt_addr_r
fdt_file => fdtfile
Signed-off-by: Yunus Bas <y.bas@phytec.de>