firmware-<qcom-msm8916>: adjust for new venus firmware path
Linux 6.7-rc1 looks for the venus (video) firmware in
qcom/venus-1.8/venus.mbn
instead of qcom/venus-1.8/venus.mdt
.
Let's install it in both places with a symlink so that the firmware packages work for both older and newer Linux versions.
Cc: @TravMurav