There are several thousand files in the test directory which we don't need.
Adding these for the native and target sysroots is a crazy amount of files
to be throwing around needlessly. Delete the files from the sysroot side
of things to tidy up the sysroots and improve performance.
(From OE-Core rev: f6bced03011ad1663d68b0322a2f8aeb4d836646)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
