sh: Drop support for memory hotplug and memory hotremove

Support for memory hotplug was restricted to 64-bit platforms in
7ec58a2b ("mm/memory_hotplug: restrict CONFIG_MEMORY_HOTPLUG
to 64 bit") while sh is a pure 32-bit platform since the removal
of sh5 support. Thus, drop support for memory hotplug and the
associated memory hotremove on this platform.

Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20240518115808.8888-2-osalvador@suse.de


Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>