Merge pull request #12728 from jeromecoutant/PR_ETHERNET_THREADSIZE

STM32 EMAC : increase thread-stacksize

Author: 0xc0170

features/netsocket/emac-drivers/TARGET_STM/mbed_lib.json

@@ -5,7 +5,7 @@
         "eth-txbufnb": 4,
         "thread-stacksize": {
             "help": "Stack size for stm32_emac_thread",
-            "value": 512
+            "value": 1024
         },
         "eth-phy-address": {
             "help" : "Configures actual PHY address according to pullup/down status of PHYAD pin(s)",