heap_caps_add_region() function

Add a region of memory to the collection of heaps at runtime. Most memory regions are defined in soc_memory_layout.c for the SoC, and are registered via heap_caps_init(). Some regions can't be used immediately and are later enabled via heap_caps_enable_nonos_stack_heaps(). Call this function to add a region of memory to the heap at some later time. This function does not consider any of the "reserved" regions or other data in soc_memory_layout, caller needs to consider this themselves. All memory within the region specified by start & end parameters must be otherwise unused. The capabilities of the newly registered memory will be determined by the start address, as looked up in the regions specified in soc_memory_layout.c. Use heap_caps_add_region_with_caps() to register a region with custom capabilities.