package/weston: un-break the rpi-compositor

The rpi-compositor was broken with the 1.4.0 release,
but we now have a fix from upstream.

Add this patch, and remove the 'depends on BROKEN'.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>