brcm47xx: do not use GPIO configuration of WRT54G for every unknown Linksys device

Most of the Linksys devices without an own GPIO configuration where
detected as WRT54G. On one board this made OpenWrt to boot into
failsafe every time, because one GPIO configurated as button was not a
button.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

SVN-Revision: 37970

package/kernel/broadcom-diag/src/diag.c

@@ -1176,8 +1176,9 @@ static struct platform_t __init *platform_detect_legacy(void)
 			if (!strcmp(boardtype, "0x0101") && !strcmp(getvar("boot_ver"), "v3.6"))
 				return &platforms[WRT54G3G];
 
-			/* default to WRT54G */
-			return &platforms[WRT54G];
+			/* default to WRT54G if no boot_hw_model is set */
+			if (nvram_get("boot_hw_model") == NULL)
+				return &platforms[WRT54G];
 		}
 		if (!strcmp(boardnum, "1024") && !strcmp(boardtype, "0x0446"))
 			return &platforms[WAP54GV2];