stm32/boards/stm32f429.ld: Increase uPy heap size by 64k for F429 MCU.
The F429 has 256k total RAM, with 64k already set aside for flash write
cache, so the uPy heap can be increased this much.
@@ -26,4 +26,4 @@ _estack = ORIGIN(RAM) + LENGTH(RAM);
_ram_start = ORIGIN(RAM);
_ram_end = ORIGIN(RAM) + LENGTH(RAM);
_heap_start = _ebss; /* heap starts just after statically allocated memory */
-_heap_end = 0x2001c000; /* tunable */
+_heap_end = 0x2002c000; /* tunable */
