Integrate meta-seco-imx/u-boot-seco-imx/seco_lf_v2021.04-gm_d18_spl
requested to merge integrate/meta-seco-imx/u-boot-seco-imx/seco_lf_v2021.04-gm_d18_spl/into/kirkstone into kirkstone
Integrate u-boot-seco-imx/seco_lf_v2021.04-gm_d18_spl
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[D18] fix SPL boot from eMMC
- fix the address to load U-Boot from, that was set incorrectly in case of boot from eMMC
- add the defconfig options for the eMMC to SPL