ARM: Add Gemini architecture v3

Adds support for Cortina Systems Gemini family CPUs:
http://www.cortina-systems.com/products/category/18

v3:
- fixed __io(a) to be defined as __typesafe_io(a)

v2:
- #include <asm/io.h> -> <linux/io.h>
- remove asm/system.h include
- revorked mm.c to use named initializers
- removed "empty" dma.h
- updated copyrights

Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index d29f926..56e13bf 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -108,6 +108,7 @@
  machine-$(CONFIG_ARCH_PXA)	   := pxa
  machine-$(CONFIG_ARCH_L7200)	   := l7200
  machine-$(CONFIG_ARCH_INTEGRATOR) := integrator
+ machine-$(CONFIG_ARCH_GEMINI)     := gemini
  textofs-$(CONFIG_ARCH_CLPS711X)   := 0x00028000
  machine-$(CONFIG_ARCH_CLPS711X)   := clps711x
  machine-$(CONFIG_ARCH_IOP32X)	   := iop32x