alpha: remove ARCH_WANT_OPTIONAL_GPIOLIB

This symbols is not needed to get access to selecting the
GPIOLIB anymore: any arch can select GPIOLIB.

Cc: Michael Büsch <m@bues.ch>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: linux-alpha@vger.kernel.org
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/alpha/Kconfig

@@ -13,7 +13,6 @@ config ALPHA
 	select GENERIC_IRQ_PROBE
 	select AUTO_IRQ_AFFINITY if SMP
 	select GENERIC_IRQ_SHOW
-	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE