ARM: gemini: get platform to build again

There is no defconfig file for gemini, which has lead to a lot
of bitrot. This makes the broken board files, the gpio implementation
and the reset logic work again, and fixes the build warnings
that got introduced with the changes to the readl/writel prototypes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5b71469..78f31a3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -411,6 +411,7 @@
 	bool "Cortina Systems Gemini"
 	select ARCH_REQUIRE_GPIOLIB
 	select ARCH_USES_GETTIMEOFFSET
+	select NEED_MACH_GPIO_H
 	select CPU_FA526
 	help
 	  Support for the Cortina Systems Gemini family SoCs