Fix MACH_TYPE for the AT91RM9200DK board.

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
diff --git a/board/atmel/at91rm9200dk/at91rm9200dk.c b/board/atmel/at91rm9200dk/at91rm9200dk.c
index c564f73..b89a3fd 100644
--- a/board/atmel/at91rm9200dk/at91rm9200dk.c
+++ b/board/atmel/at91rm9200dk/at91rm9200dk.c
@@ -47,7 +47,7 @@
 	/* so we do _nothing_ here */
 
 	/* arch number of AT91RM9200DK-Board */
-	gd->bd->bi_arch_number = MACH_TYPE_AT91RM9200;
+	gd->bd->bi_arch_number = MACH_TYPE_AT91RM9200DK;
 	/* adress of boot parameters */
 	gd->bd->bi_boot_params = PHYS_SDRAM + 0x100;