[POWERPC] Fix the ability to reset on MPC8544 DS and MPC8568 MDS boards

Add global-utilities node with has-rstcr on MPC8544 DS and MPC8568 MDS
boards so they are able to reset properly.

Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>