Fix freertos sys examples (#499)

Increase stack size.

Author: peterharperuk

pico_w/wifi/freertos/FreeRTOSConfig_examples_common.h

@@ -47,7 +47,7 @@
 #define configUSE_TICK_HOOK                     0
 #define configTICK_RATE_HZ                      ( ( TickType_t ) 1000 )
 #define configMAX_PRIORITIES                    32
-#define configMINIMAL_STACK_SIZE                ( configSTACK_DEPTH_TYPE ) 256 
+#define configMINIMAL_STACK_SIZE                ( configSTACK_DEPTH_TYPE ) 512
 #define configUSE_16_BIT_TICKS                  0
 
 #define configIDLE_SHOULD_YIELD                 1

pico_w/wifi/freertos/ping/lwipopts.h

@@ -9,7 +9,7 @@
 
 #if !NO_SYS
 #define TCPIP_THREAD_STACKSIZE 1024
-#define DEFAULT_THREAD_STACKSIZE 1024
+#define DEFAULT_THREAD_STACKSIZE 2048
 #define DEFAULT_RAW_RECVMBOX_SIZE 8
 #define TCPIP_MBOX_SIZE 8
 #define LWIP_TIMEVAL_PRIVATE 0