Finally eradicate CONFIG_HOTPLUG

Ever since commit 45f035ab9b8f ("CONFIG_HOTPLUG should be always on"),
it has been basically impossible to build a kernel with CONFIG_HOTPLUG
turned off.  Remove all the remaining references to it.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/mm/Kconfig b/mm/Kconfig
index e742d06..f5e698e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -173,7 +173,7 @@
 config MEMORY_HOTPLUG
 	bool "Allow for memory hot-add"
 	depends on SPARSEMEM || X86_64_ACPI_NUMA
-	depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
+	depends on ARCH_ENABLE_MEMORY_HOTPLUG
 	depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
 
 config MEMORY_HOTPLUG_SPARSE