fwget: fix installing multiple firmware files

Remove quotes around the list of packages to install.
Otherwise pkg is only fed one argument which results in a
non-working solution:
pkg: No packages available to install matching 'wifi-firmware-ath10k-kmod wifi-firmware-mt76-kmod wifi-firmware-ath11k-kmod' have been found in the repositories

MFC after: 10 days
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D41474

fwget: Fix quoting

This kind of quoting doesn't work, no idea why shellcheck wanted this.
If there is a "safer" way to "fix" this feel free to do it just test
that it's working after.

Reported by: Kenneth Raplee <kenrap@kennethraplee.com>
Sponsored by: Beckhoff Automation GmbH & Co. KG
Fixes: 7ad4d94d5bf2 ("Fix some shell issues by adding quotes and replace backticks with $()")

Fix some shell issues by adding quotes and replace backticks with $()

This patch fixes the following issues reported by shellcheck:
- Quote default assignments (SC2223)
- Use $() instead of backticks (SC2006)
- Double quote $@ (SC2068)
- Double quote variables in if-statements and other places (SC2086)

While here, fix a whitespace at one end of line instance in the license
text.

Approved by: manu
Differential Revision: https://reviews.freebsd.org/D40604

fwget: Always install packages

This wasn't done before as -y wasn't added to the pkg install line.

Sponsored by: Beckhoff Automation GmbH & Co. KG

fwget: remove logging redirects

After adding addpkg() in 10aa369afd9946da18ae51b07aeadc3314fba56d
the redirects are no longer needed. We can now log directly so
simplify the code.

Reported by: manu
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D40077

fwget: simplify adding firmware images to pkg to install

Rather than using echo to return the firmware package name, call a
new function (addpkg) which will also deal with (i) no leading space
and (ii) remove duplicates (as some devices have dual-wifi-cards).
In addition we won't have a line break when having multiple packages.

While here also do not call pkg(8) anymore if there is no package to
install and use the correct variable to install all and not just the
last found package.

Reviewed by: manu, bapt
Differential Revision: https://reviews.freebsd.org/D40071

fwget: Use BSD-2-Clause instead of BSD-2-Clause-FreeBSD

Reported by: bz
Sponsored by: Beckhoff Automation GmbH & Co. KG

fwget: Introduce new utility

This script's goal is to check the system for peripherals that needs
firmware and install the needed packages for them.
For now it only support pci subsystem and only video classes for AMD
and Intel GPUs.

Reviewed by: bapt
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D39825