sniper: Serial number support, obtained from die ID

The OMAP3 has some die-specific ID bits that we can use to give the device a
(more or less) unique serial number. This is particularly useful for e.g. USB.
Signed-off-by: NPaul Kocialkowski <contact@paulk.fr>

board/lge/sniper/sniper.c

@@ -70,7 +70,9 @@ int board_init(void)
 
 int misc_init_r(void)
 {
+	char serial_string[17] = { 0 };
 	char reboot_mode[2] = { 0 };
+	u32 dieid[4] = { 0 };
 
 	/* Reboot mode */
 
@@ -82,6 +84,17 @@ int misc_init_r(void)
 		omap_reboot_mode_clear();
 	}
 
+	/* Serial number */
+
+	get_dieid((u32 *)&dieid);
+
+	if (!getenv("serial#")) {
+		snprintf(serial_string, sizeof(serial_string),
+			"%08x%08x", dieid[0], dieid[3]);
+
+		setenv("serial#", serial_string);
+	}
+
 	return 0;
 }