metag: 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: linux-metag@vger.kernel.org
Acked-by: NJames Hogan <james.hogan@imgtec.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

arch/metag/Kconfig.soc

@@ -16,7 +16,6 @@ config META21_FPGA
 
 config SOC_TZ1090
 	bool "Toumaz Xenif TZ1090 SoC (Comet)"
-	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select IMGPDC_IRQ
 	select METAG_LNKGET_AROUND_CACHE
 	select METAG_META21