Heap size adjusted to work for both tls-client and mbed-client

Targets NUCLEO_F429ZI and UBLOX_EVK_ODIN_W2 have 192K RAM.
Heap size in PR #3871 was increased from 48K to 96K as tls-client
example failed with 48K heap. But this resulted in compilation failures
in mbed-client that requires 71K for global/static data.
Hence this PR reduces heap to 64K that minimum required by tls-client
to work. This also meets mbed-client data segment requirements.

Author: Mohammad Azim Khan

targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F429xI/device/TOOLCHAIN_IAR/stm32f429xx_flash.icf

@@ -15,9 +15,9 @@ define symbol __ICFEDIT_region_RAM_end__      = 0x2002FFFF;
 define symbol __ICFEDIT_region_CCMRAM_start__ = 0x10000000;
 define symbol __ICFEDIT_region_CCMRAM_end__   = 0x1000FFFF;
 /*-Sizes-*/
-/*Heap 1/2 of ram and stack 1/8*/
+/*Heap 64K and stack 24K */
 define symbol __ICFEDIT_size_cstack__ = 0x6000;
-define symbol __ICFEDIT_size_heap__   = 0x18000;
+define symbol __ICFEDIT_size_heap__   = 0x10000;
 /**** End of ICF editor section. ###ICF###*/
 
 

targets/TARGET_STM/TARGET_STM32F4/TARGET_UBLOX_EVK_ODIN_W2/device/TOOLCHAIN_IAR/stm32f439xx_flash.icf

@@ -15,9 +15,9 @@ define symbol __ICFEDIT_region_RAM_end__      = 0x2002FFFF;
 define symbol __ICFEDIT_region_CCMRAM_start__ = 0x10000000;
 define symbol __ICFEDIT_region_CCMRAM_end__   = 0x1000FFFF;
 /*-Sizes-*/
-/*Heap 1/2 of ram and stack 1/8*/
+/*Heap 64kB and stack 24kB */
 define symbol __ICFEDIT_size_cstack__ = 0x6000;
-define symbol __ICFEDIT_size_heap__   = 0x18000;
+define symbol __ICFEDIT_size_heap__   = 0x10000;
 /**** End of ICF editor section. ###ICF###*/