IPQ806x AP148 and DB149 boards didn't have the UCI ubootenv
section initialized, so the usage of fw_printenv required manual
configuration. With this change, the "fw_printenv" and "fw_setenv"
command will automatically work on NOR and NAND based platforms.
Signed-off-by: Ram Chandra Jangir <rjangir@codeaurora.org>