blackfin: do away with ARCH_REQUIRE_GPIOLIB

Replace "select ARCH_REQUIRE_GPIOLIB" with "select GPIOLIB"
as this can now be selected directly.

Cc: Michael Büsch <m@bues.ch>
Cc: Steven Miao <realmz6@gmail.com>
Cc: adi-buildroot-devel@lists.sourceforge.net
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

arch/blackfin/Kconfig

@@ -26,7 +26,7 @@ config BLACKFIN
 	select HAVE_OPROFILE
 	select HAVE_PERF_EVENTS
 	select ARCH_HAVE_CUSTOM_GPIO_H
-	select ARCH_REQUIRE_GPIOLIB
+	select GPIOLIB
 	select HAVE_UID16
 	select HAVE_UNDERSCORE_SYMBOL_PREFIX
 	select VIRT_TO_BUS