heap: Remove size check in multi_heap.c when registering a new heap

The tlsf now checks for size validity when creating a new heap.

The check previously done in multi_heap_register_impl() is no longer
valid since the tlsf_size() is not known at this time (as the metadata
size is linked ot the size of the memory region passed as parameter
when calling tlsf_create_with_pool())

The tlsf_create_with_pool() will return a null pointer if the size
of the memory is not big enough to hold the metadata overhead and
at least a small block.

Update the test according to the changes in TLSF API

components/heap/multi_heap.c

@@ -142,7 +142,7 @@ size_t multi_heap_get_allocated_size_impl(multi_heap_handle_t heap, void *p)
 multi_heap_handle_t multi_heap_register_impl(void *start_ptr, size_t size)
 {
     assert(start_ptr);
-    if(size < (tlsf_size(NULL) + tlsf_block_size_min() + sizeof(heap_t))) {
+    if(size < (sizeof(heap_t))) {
         //Region too small to be a heap.
         return NULL;
     }