mirrors: Drop obsolete/inappropriate OE/YP mirror entries
These fetchers aren't used by code that would end up on these mirrors and are about
to be removed anyway in some cases. Drop the pointless/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>