Currently if a tune isn't specified in the table, the loader defaults for the
architecture are used which may or may not match our path specification. This
leads to general confusion.
Change the code to use the linuxloader class which works of architecture, not
tune.
This still isn't perfect as n32/x32 aren't covered but its an improvement
to listing all tunes here.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
