drivers: base: reduce add_memory_section() for boot-time only

Now that add_memory_section() is only called from boot time, reduce
the logic and remove the enum.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/base/memory.c
Simple merge

diff --cc include/linux/memory.h
Simple merge