powerpc/8xx: Remove loading of r10 at end of FixupDAR

Since commit 2321f337

, r10 is not used anymore
after FixupDAR. There is therefore no need to set it up with the value of DAR.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>