xserver-xorg: fix qa warnings

xserver-xorg: fix qa warnings

When build lib32-xserver-xorg it has qa warning:

| WARNING: lib32-xserver-xorg-2_1.18.4-r0 do_package_qa: QA Issue:
| Package lib32-xf86-video-modesetting contains Xorg driver
| (modesetting_drv.so) but no xorg-abi- dependencies [xorg-driver-abi]

The qa check xorg-driver-abi has been skipped for xserver-xorg and make
it to skip for multilib package too.

Signed-off-by: Kai Kang <kai.kang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>