mx31ads: Place machine ID into board config

Let common code set the machine ID.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>

board/freescale/mx31ads/mx31ads.c

@@ -99,7 +99,6 @@ int board_early_init_f(void)
 
 int board_init(void)
 {
-	gd->bd->bi_arch_number = MACH_TYPE_MX31ADS;	/* board id for linux */
 	gd->bd->bi_boot_params = 0x80000100;	/* adress of boot parameters */
 
 	return 0;

include/configs/mx31ads.h

@@ -35,6 +35,8 @@
 
 #define CONFIG_SYS_TEXT_BASE		0xA0000000
 
+#define CONFIG_MACH_TYPE	MACH_TYPE_MX31ADS
+
 /*
  * Disabled for now due to build problems under Debian and a significant increase
  * in the final file size: 144260 vs. 109536 Bytes.