imlib2: imlib2-config: delete old reference to @my_libs@

The script "imlib2-config" returns "@my_libs@" that causes build failures
on the programs that use it.
This is a regression of version v1.4.6.

Add a upstream patch to fix it and reorder the patches to follow
upstream branch order.

Fixes:
http://autobuild.buildroot.net/results/e1a7691a6528d635c308d7bf47a8be8aa0594190
http://autobuild.buildroot.net/results/23fea2e4d668d69565d5f50493635fc834c54ce1



Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>