tile: remove duplicate CONFIG_HOTPLUG definition

As part of the plan to remove CONFIG_HOTPLUG, it was found that tile
duplicates this config option for no reason (it's already defined as part of
init/Kconfig).  This patch removes it from the tile-only Kconfig file.

Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>