Misc cleanup/fixes for firmware on MSM8916 devices

3 separate (minor) changes, thought it's faster if I submit them as one MR:

• motorola-osprey: use firmware from harpia (cc @MartijnBraam)

  The files packaged in firmware-motorola-osprey-wcnss-nv and firmware-motorola-osprey-venus seem completely identical to those of harpia, so there is no need to package them twice. There are some differences in modem/wcnss firmware but those are now covered by the msm-firmware-loader.

• xiaomi-wt88047: fix replaces/provides of subpackages (cc @TravMurav)

  The "replaces"/"provides" should have the full package name, not just the part of the subpackage. Also, the nonfree-firmware subpackage does not need it because the old "device-xiaomi-wt88047-nonfree-firmware-modem-wt88047" packages were only install_if packages without any files installed.

• asus-z00l: stop installing venus firmware (cc @antonyjr)

  Apparently this firmware is also available via the msm-firmware-loader already so there is no need to redistribute this and waste space on rootfs.

• firmware-<msm8916>: drop unused firmware subpackages

  The firmware provided by these subpackages is now covered by the msm-firmware-loader, so there is no need to build packages for them anymore.