openthread posix platform config missing setting to fully enable TREL

[3oris]

In https://github.com/SiliconLabs/simplicity_sdk/blob/sisdk-2024.6/protocol/openthread/platform-abstraction/posix/openthread-core-silabs-posix-config.h#L41 ff and the likes

OTBR_TREL=ON is missing from the documentation on certified OTBRs (at least for thread 1.4). It doesn't suffice to use the openthread-core-silabs-posix-config.h in an original https://github.com/openthread/ot-br-posix checkout (as advised in your release PDFs).

You have to use at least

sudo INFRA_IF_NAME=eth0 \
     RELEASE=1 REFERENCE_DEVICE=1 BACKBONE_ROUTER=1 BORDER_ROUTING=1 NAT64=1 DNS64=1 \
     OTBR_OPTIONS="-DOT_THREAD_VERSION=1.4 \
                   -DOT_PLATFORM_CONFIG=openthread-core-silabs-posix-config.h \
                   -DOTBR_DUA_ROUTING=ON OTBR_TREL=ON -DOTBR_DNSSD_DISCOVERY_PROXY=ON -DOTBR_SRP_ADVERTISING_PROXY=ON" \

Please see: openthread/ot-br-posix#2484