libre: uboot4extlinux-sunxi: fix missing python-setuptools
    
    When building uboot4extlinux-sunxi with libremakepkg we have
    the following error:
     |    BINMAN  all
     |  Traceback (most recent call last):
     |    File "/build/uboot4extlinux-sunxi/src/u-boot-2021.07/./tools/binman/binman", line 39, in <module>
     |      from binman import control
     |    File "/build/uboot4extlinux-sunxi/src/u-boot-2021.07/tools/binman/../binman/control.py", line 11, in <module>
     |      import pkg_resources
     |  ModuleNotFoundError: No module named 'pkg_resources'
     |  make: *** [Makefile:1084: all] Error 1
     |  ==> ERROR: A failure occurred in build().
    
    In u-boot 2021.07 in tools/binman/control.py, line 11 we have:
        import pkg_resources
    
    To find the package having pkg_resources we can use python to find
    the files implementing it:
        $ python
        Python 3.9.5 (default, May 27 2021, 07:33:37)
        [GCC 11.1.0] on linux
        Type "help", "copyright", "credits" or "license" for more information.
        >>> import pkg_resources
        >>> help(pkg_resources)
    At the end of the help we see the following:
        FILE
            /usr/lib/python3.9/site-packages/pkg_resources/__init__.py
    
    And we can finally use pacman to find the package having that file:
        $ pacman -Q -o /usr/lib/python3.9/site-packages/pkg_resources/__init__.py
        /usr/lib/python3.9/site-packages/pkg_resources/__init__.py
        is owned by python-setuptools 1:52.0.0-1.0
    
    Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>