hexagon: update TODO list

The symbol that will be selected when GPIO is implemented
for Hexagon will be GPIOLIB, we have removed
ARCH_REQUIRE_GPIOLIB and ARCH_WANT_OPTIONAL_GPIOLIB.

Cc: Michael Büsch <m@bues.ch>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-hexagon@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/hexagon/Kconfig

@@ -8,8 +8,7 @@ config HEXAGON
 	# select HAVE_REGS_AND_STACK_ACCESS_API
 	# select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	# select ARCH_HAS_CPU_IDLE_WAIT
-	# select ARCH_WANT_OPTIONAL_GPIOLIB
-	# select ARCH_REQUIRE_GPIOLIB
+	# select GPIOLIB
 	# select HAVE_CLK
 	# select GENERIC_PENDING_IRQ if SMP
 	select GENERIC_ATOMIC64