I have the same issue.
Adding the following to your build/conf/bblayers.conf should help:
BBLAYERS += " ${BSPDIR}/sources/meta-fsl-bsp-release/imx/meta-bsp "
BBLAYERS += " ${BSPDIR}/sources/meta-fsl-bsp-release/imx/meta-sdk "
For things to build properly you also might need the following:
BBLAYERS += " ${BSPDIR}/sources/meta-browser "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-gnome "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-networking "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-python "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-ruby "
BBLAYERS += " ${BSPDIR}/sources/meta-openembedded/meta-filesystems "
BBLAYERS += " ${BSPDIR}/sources/meta-qt5 "
Greets,
Pieter