Hints for firmware-libertas in non-free

Hints

• asv-driver-firmware-description-missing
  firmware-libertas.metainfo.xml -
  It is recommended to add a long description to this component to present it better to users.
• asv-summary-has-dot-suffix
  firmware-libertas.metainfo.xml:5 - Binary firmware for wireless network cards with Marvell and NXP 88W8xxx chips supported by the libertas_cs, libertas_sdio, libertas_spi, libertas_tf_usb, mwifiex_pcie, mwifiex_sdio, mwifiex_usb, mwl8k and usb8xxx drivers.
  The component summary should not end with a dot (`.`).