Commit f615136c06a7 ("xtensa: add SMP support") added "select
USE_GENERIC_SMP_HELPERS". But the Kconfig symbol USE_GENERIC_SMP_HELPERS
was already removed in v3.13, so that select is a nop. Drop it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>