roms/Makefile.edk2: update input file list for "pc-bios/edk2-licenses.txt"

roms/Makefile.edk2: update input file list for "pc-bios/edk2-licenses.txt"

(1) For TianoCore Bugzilla

      https://bugzilla.tianocore.org/show_bug.cgi?id=1373

    the majority of the edk2 tree was relicensed under the
    BSD-2-Clause-Patent license:

      https://spdx.org/licenses/BSD-2-Clause-Patent.html>

    Edk2 commit f53de8aecb12 ("edk2: Add License-History.txt", 2019-04-09)
    added a new file called "License-History.txt", describing license and
    contributor agreement changes over time.

(2) For advacing edk2's OpenSSL git submodule to the 1.1.1b release, a
    more up-to-date ArmSoftFloatLib instance became necessary, on 32-bit
    ARM. Therefore, the embedded (and by now, obsolete) Berkeley SoftFloat
    library was replaced with a git submodule of the same, checked out at
    the latest release ("3e", plus a typo fix on top -- commit
    b64af41c3276). This was implemented for TianoCore Bugzilla

      https://bugzilla.tianocore.org/show_bug.cgi?id=1845

    in edk2 commit range b6cfa686e42d..371e7001e8d5.

Include the edk2 project's "License-History.txt" file, and the Berkeley
SoftFloat library's "COPYING.txt", in our generated
"pc-bios/edk2-licenses.txt" text file.

Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugs.launchpad.net/qemu/+bug/1831477
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>