Increase the thread stack size on FastModel targets

The thread stack size was restricted due to some boards have really limited RAM sizes,
and out of heap memory on multiple threads tests.
The side effect was on the debug profile build, the tests will get stack overflow.
We need the build the test with debug profile in order to do the code coverage analysis.
So increased the thread stack size on FastModel targets.

TESTS/mbedmicro-rtos-mbed/basic/main.cpp

@@ -31,6 +31,8 @@ using utest::v1::Case;
 
 #if defined(__CORTEX_M23) || defined(__CORTEX_M33)
 #define TEST_STACK_SIZE 512
+#elif defined(__ARM_FM)
+#define TEST_STACK_SIZE 512
 #else
 #define TEST_STACK_SIZE 256
 #endif

TESTS/mbedmicro-rtos-mbed/mail/main.cpp

@@ -31,6 +31,8 @@ using namespace utest::v1;
 
 #if defined(__CORTEX_M23) || defined(__CORTEX_M33)
 #define THREAD_STACK_SIZE   512
+#elif defined(__ARM_FM)
+#define THREAD_STACK_SIZE   512
 #else
 #define THREAD_STACK_SIZE   320 /* larger stack cause out of heap memory on some 16kB RAM boards in multi thread test*/
 #endif

TESTS/mbedmicro-rtos-mbed/malloc/main.cpp

@@ -39,6 +39,8 @@ volatile bool thread_should_continue = true;
 #define THREAD_STACK_SIZE   512
 #elif defined(__CORTEX_M23) || defined(__CORTEX_M33)
 #define THREAD_STACK_SIZE   512
+#elif defined(__ARM_FM)
+#define THREAD_STACK_SIZE   512
 #else
 #define THREAD_STACK_SIZE   256
 #endif

TESTS/mbedmicro-rtos-mbed/threads/main.cpp

@@ -34,6 +34,8 @@
 #define PARALLEL_THREAD_STACK_SIZE 512
 #elif defined(__CORTEX_M23) || defined(__CORTEX_M33)
 #define PARALLEL_THREAD_STACK_SIZE 512
+#elif defined(__ARM_FM)
+#define PARALLEL_THREAD_STACK_SIZE 512
 #else
 #define PARALLEL_THREAD_STACK_SIZE 384
 #endif