LED class support is needed by the ideapad-laptop module to compile after
the referenced commit. Add missing NEW_LEDS and LEDS_CLASS to Kconfig.

Fixes: 503325f8 ("platform/x86: ideapad-laptop: add keyboard backlight control support")
Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210204142010.356675-1-pobrn@protonmail.comSigned-off-by: Hans de Goede <hdegoede@redhat.com>