(fix:mp) extend micropython heap by 10kb

There is 10kb remaining as a buffer when the micropython and newlib
heaps were co-existing - it is now a compile error to use the newlib
heap on core1.

pycardium/main.c

@@ -50,7 +50,7 @@ int main(void)
 	mp_stack_set_top(&__StackTop);
 	mp_stack_set_limit((mp_int_t)&__StackLimit);
 
-	gc_init(&__HeapBase + 1024 * 10, &__HeapLimit);
+	gc_init(&__HeapBase, &__HeapLimit);
 
 	mp_init();