mach-ux500: Kconfig for snowball board

This adds the necessary Kconfig entry for a Snowball board.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>

arch/arm/mach-ux500/Kconfig

@@ -35,6 +35,13 @@ config MACH_HREFV60
        help
          Include support for the HREFv60 new development platform.
 
+config MACH_SNOWBALL
+	bool "U8500 Snowball platform"
+	depends on UX500_SOC_DB8500
+	select MACH_U8500
+	help
+	  Include support for the snowball development platform.
+
 config MACH_U5500
 	bool "U5500 Development platform"
 	depends on UX500_SOC_DB5500