You could edit build_t1040d4rdb/conf/local.conf add the following line, then run bitbake to rebuild rootfs.
IMAGE_INSTALL_append = " bridge-utils"
In fact, if you run "bitbake fsl-image-core" the package bridge-utils will be included in rootfs automatically.
Please refer to recipe meta-freescale/recipes-fsl/packagegroups/packagegroup-fsl-networking-core.bb, "bridge-utils" package has been added in RDEPENDS_${PN} as the following.
RDEPENDS_${PN} = " \
bridge-utils \
ethtool \
iproute2 \
iproute2-tc \
iptables \
iputils \
inetutils \
"packagegroup-fsl-networking-core" has been included in meta-freescale/recipes-fsl/images/fsl-image-core.bb as the following.
IMAGE_INSTALL_append = " \
packagegroup-fsl-tools-core \
packagegroup-fsl-benchmark-core \
packagegroup-fsl-networking-core \
