mx28evk: Use 512k for fdt partition to align it

Using 512k for fdt partition allow it to be aligned with the other
small partitions and 512k erase block size.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Stefano Babic <sbabic@denx.de>

include/configs/mx28evk.h

@@ -96,7 +96,7 @@
 		"512k(environment),"		\
 		"512k(redundant-environment),"	\
 		"4m(kernel),"			\
-		"128k(fdt),"			\
+		"512k(fdt),"			\
 		"8m(ramdisk),"			\
 		"-(filesystem)"
 #endif