arm: Add Initial TI-Nspire support

This patch adds support for the TI-Nspire platform.

Changes between v1 and v2:
* Added GENERIC_IRQ_CHIP to platform Kconfig

Signed-off-by: Daniel Tang <dt.tangr@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 1ba358b..b4615aa 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -164,6 +164,7 @@
 machine-$(CONFIG_ARCH_MVEBU)		+= mvebu
 machine-$(CONFIG_ARCH_NETX)		+= netx
 machine-$(CONFIG_ARCH_NOMADIK)		+= nomadik
+machine-$(CONFIG_ARCH_NSPIRE)		+= nspire
 machine-$(CONFIG_ARCH_OMAP1)		+= omap1
 machine-$(CONFIG_ARCH_OMAP2PLUS)	+= omap2
 machine-$(CONFIG_ARCH_ORION5X)		+= orion5x