[ARM] Fix missing declaration of cache_is_vivt()

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/ecard.c

@@ -41,6 +41,7 @@
 #include <linux/device.h>
 #include <linux/init.h>
 
+#include <asm/cacheflush.h>
 #include <asm/dma.h>
 #include <asm/ecard.h>
 #include <asm/hardware.h>