POSIX port fixes (#626)

* Fix types in POSIX port

Use TaskFunction_t and StackType_t as other ports do.

* Fix portTICK_RATE_MICROSECONDS in POSIX port

---------

Co-authored-by: Jacques GUILLOU <jacques.guillou.job@gmail.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
diff --git a/portable/ThirdParty/GCC/Posix/port.c b/portable/ThirdParty/GCC/Posix/port.c
index 82aa27b..12076b9 100644
--- a/portable/ThirdParty/GCC/Posix/port.c
+++ b/portable/ThirdParty/GCC/Posix/port.c
@@ -73,7 +73,7 @@
 typedef struct THREAD
 {
     pthread_t pthread;
-    pdTASK_CODE pxCode;
+    TaskFunction_t pxCode;
     void * pvParams;
     BaseType_t xDying;
     struct event * ev;
@@ -127,9 +127,9 @@
 /*
  * See header file for description.
  */
-portSTACK_TYPE * pxPortInitialiseStack( portSTACK_TYPE * pxTopOfStack,
-                                        portSTACK_TYPE * pxEndOfStack,
-                                        pdTASK_CODE pxCode,
+portSTACK_TYPE * pxPortInitialiseStack( StackType_t * pxTopOfStack,
+                                        StackType_t * pxEndOfStack,
+                                        TaskFunction_t pxCode,
                                         void * pvParameters )
 {
     Thread_t * thread;
diff --git a/portable/ThirdParty/GCC/Posix/portmacro.h b/portable/ThirdParty/GCC/Posix/portmacro.h
index 2061c32..6865586 100644
--- a/portable/ThirdParty/GCC/Posix/portmacro.h
+++ b/portable/ThirdParty/GCC/Posix/portmacro.h
@@ -73,7 +73,7 @@
 #define portSTACK_GROWTH            ( -1 )
 #define portHAS_STACK_OVERFLOW_CHECKING ( 1 )
 #define portTICK_PERIOD_MS          ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
-#define portTICK_RATE_MICROSECONDS  ( ( portTickType ) 1000000 / configTICK_RATE_HZ )
+#define portTICK_RATE_MICROSECONDS  ( ( TickType_t ) 1000000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT          8
 /*-----------------------------------------------------------*/