md5 (sha256) as of 70fde0ed6bbbb1f84c440190ba1e5435f8c90e13 in base
started quoting ? as \? which then goes into the distinfo file and
as a result we fail to find that file later using Mk/Scripts/.

Using the dummy=/ option is not as straight forward with a dynamic list
of distfiles as one would wish.
We now build a full matrix of MASTER_SITE x DISTFILES; that is for
each "DISTFILE" we generate a :group with a full download URL on each
"MASTER_SITE". That way each file is still possibly downloadable from
each of the various master sites.

The difference now is that the files sotred in distfiles no longer
contain the ?h=<tag> extension as we strip that for the distfile as
it is encoded in the master_site URLs.

Build that matrix needs to happen after bsd.port.pre.mk is included
as otherwise FLAVOR is not set correctly and we do not build the
correct set of firmware files as requested.

Adjust the remainder of the Makefile.inc to deal with the fact that
the tag is no longer part of the file name.

In order to not store files in the same place if they change between
version, we now hash the distfiles linux-firmware directories by tag
as well.

With a bit more cleanup I should one day look into making this a
USES=linuxfw or similar so it can more easily be re-used for other
firmware as well.

Sponsored by: The FreeBSD Foundation