oeqa/selftest/buildoptions: Drop pointless/obsolete mirror entries

oeqa/selftest/buildoptions: Drop pointless/obsolete mirror entries

We've never had any of these sources on this mirror and support for
several is about to be removed in the fetchers anyway. Drop the
obsolete entries.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>