powerpc/mpc8572ds: Increase u-boot size to 768KB

U-boot image has grown and exceeded the predefined 512KB. Increasing to
768KB to align with other powerpc boards. Tested on MPC8572DS for 32-
and 36-bit targets with NOR flash boot. NAND boot is not covered by
this patch.

Also update board maintainer for these boards.

Signed-off-by: York Sun <yorksun@freescale.com>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/include/configs/MPC8572DS.h b/include/configs/MPC8572DS.h
index 7b63945..3a30feb 100644
--- a/include/configs/MPC8572DS.h
+++ b/include/configs/MPC8572DS.h
@@ -30,7 +30,7 @@
 #endif
 
 #ifndef CONFIG_SYS_TEXT_BASE
-#define CONFIG_SYS_TEXT_BASE	0xeff80000
+#define CONFIG_SYS_TEXT_BASE	0xeff40000
 #endif
 
 #ifndef CONFIG_RESET_VECTOR_ADDRESS