Revert "Adjusting Stack size Allocation (IAR, LPC176x)"

This reverts commit fce2ca2.

Author: 0xc0170

targets/TARGET_NXP/TARGET_LPC176X/device/TOOLCHAIN_IAR/LPC17xx.icf

@@ -12,10 +12,9 @@ define symbol __ICFEDIT_region_RAM_start__   = 0x100000C8;
 define symbol __ICFEDIT_region_RAM_end__     = 0x10007FDF;
 
 /*-Sizes-*/
-/* Heap 7K, Vector table stack about 4K (this is actual stack size in mbed-os 2) */
+/*Heap 1/4 of ram and stack 1/8*/
 define symbol __ICFEDIT_size_cstack__   = 0x1000;
-define symbol __ICFEDIT_size_heap__     = 0x1C00;
-
+define symbol __ICFEDIT_size_heap__     = 0x2000;
 /**** End of ICF editor section. ###ICF###*/
 
 define symbol __CRP_start__   = 0x000002FC;