gpio: select ANON_INODES

The build servers found that gpiolib is using ANON_INODES but
has forgotten to select it. Fix this.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -33,6 +33,7 @@ config ARCH_REQUIRE_GPIOLIB
 
 menuconfig GPIOLIB
 	bool "GPIO Support"
+	select ANON_INODES
 	help
 	  This enables GPIO support through the generic GPIO library.
 	  You only need to enable this, if you also want to enable