[poky] How to append inc file

[Yu Ke]

Hi,

bbappend file can be used to append content to bb file, and it is very 
useful in BSP meta data. Today I just find the *.inc file is also need 
to be appended, so I wonder if there is similar incappend file that can 
append content to inc file?

I meet this requirement when trying to fix bug 896 
(http://bugzilla.yoctoproject.org/show_bug.cgi?id=896). To make 
poky-image-clutter build pass in n450, the clutter.inc need to be 
appended to change the COMPATIBLE_MACHINE.

Regards
Ke