[oe] xorg recipes cleanup

[Martin Jansa]

Hi,

all distributions are now using 
preferred-xorg-versions-X11R7.5.inc or
preferred-xorg-versions-live.inc or
no preferred-xorg-versions*.inc at all

So we can remove some older versions not pinned in those 2 
to make future maintanance of xorg-* dirs a bit easier.

As this is really easy to test (if you apply all 9 and build your 
favourite target again, no xorg package should be rebuilt - version changed),
please test and ACK or don't scream later that you had some strange version
preferred from local.conf.

Thanks,