This is supposed to be a build-system flag. Move it there so we can
define it before linux/kconfig.h is included.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add imximage-8mp-lpddr4.cfg for imximage usage, almost same
as i.MX8MN ddr4 cfg, but with different ddr firmware
Signed-off-by: Peng Fan <peng.fan@nxp.com>