mel-support: add firmware-wireless recipe

This has a subset of linux-firmware, just with the wireless firmware.

JIRA: SB-2784

Signed-off-by: Christopher Larson <kergoth@gmail.com>
mel: for minnow, use firmware-wireless

Rather than all of linux-firmware, just use the wireless firmware from it, as
this is all we care about, and leaves fewer licenses to deal with.

JIRA: SB-2784

Signed-off-by: Christopher Larson <kergoth@gmail.com>
Merge remote-tracking branch 'kergoth/sb-2784' into sb-2784

* kergoth/sb-2784:
  mel: for minnow, use firmware-wireless
  mel-support: add firmware-wireless recipe