kvm/powerpc: flat device tree files for MPC8544DS

mpc8544ds.dts is copied from kerenl.
Non-supported devices has been removed.

Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6664 c046a42c-6fe2-441c-8c8c-71466251a162