manifests: default.xml: bump meta-seco-imx

SBC-C61: update Linux 5.10 to fix Bluetooth.
defconfig: Build sdma firmware into the kernel binary.

Closes https://git.ostc-eu.org/OSTC/planning/hw-enablement/-/issues/52



Signed-off-by: Ettore Chimenti <ettore.chimenti@seco.com>