tg3: Fix 5762 NVRAM sizing

Don't set the default size to 128K if it is 5762.  Instead, rely on the
size we obtain from NVRAM location 0xf0.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/tg3.c

@@ -13883,7 +13883,8 @@ static void tg3_get_5720_nvram_info(struct tg3 *tp)
 			tp->nvram_size = TG3_NVRAM_SIZE_1MB;
 			break;
 		default:
-			tp->nvram_size = TG3_NVRAM_SIZE_128KB;
+			if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5762)
+				tp->nvram_size = TG3_NVRAM_SIZE_128KB;
 			break;
 		}
 		break;
@@ -13929,7 +13930,8 @@ static void tg3_get_5720_nvram_info(struct tg3 *tp)
 			tp->nvram_size = TG3_NVRAM_SIZE_1MB;
 			break;
 		default:
-			tp->nvram_size = TG3_NVRAM_SIZE_128KB;
+			if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5762)
+				tp->nvram_size = TG3_NVRAM_SIZE_128KB;
 			break;
 		}
 		break;