ARM: u300: only build for ARCH_MULTI_V5

This avoids impossible platform combinations, as we cannot
build a combined V5 + V6/V7 kernel.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/mach-u300/Kconfig b/arch/arm/mach-u300/Kconfig
index 09f4dda..a85adcd 100644
--- a/arch/arm/mach-u300/Kconfig
+++ b/arch/arm/mach-u300/Kconfig
@@ -3,7 +3,7 @@
 comment "ST-Ericsson Mobile Platform Products"
 
 config ARCH_U300
-	bool "ST-Ericsson U300 Series"
+	bool "ST-Ericsson U300 Series" if ARCH_MULTI_V5
 	depends on MMU
 	select ARCH_REQUIRE_GPIOLIB
 	select ARM_AMBA