Adjust STMF411xE IAR linker file to mbed-os memory needs.

Stack size decreased and heap size increased.

Author: KariHaapalehto

targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F411xE/device/TOOLCHAIN_IAR/stm32f411xe.icf

@@ -18,9 +18,9 @@ define region ROM_region = mem:[from __region_ROM_start__ to __region_ROM_end__]
 define region RAM_region = mem:[from __region_RAM_start__ to __region_RAM_end__];
 
 /* Stack and Heap */
-/*Heap 1/4 of ram and stack 1/8*/
-define symbol __size_cstack__ = 0x4000;
-define symbol __size_heap__   = 0x8000;
+/*Heap 84kB and stack 1kB */
+define symbol __size_cstack__ = 0x400;
+define symbol __size_heap__   = 0x15000;
 define block CSTACK    with alignment = 8, size = __size_cstack__   { };
 define block HEAP      with alignment = 8, size = __size_heap__     { };
 define block STACKHEAP with fixed order { block HEAP, block CSTACK };