ARM: mach-bcmring: use proper constant to identify DMA memory area

Using VMALLOC_END implies a presumption about the layout which is best
avoided, even if in practice this would not change much.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>

arch/arm/mach-bcmring/dma.c

@@ -1614,7 +1614,7 @@ DMA_MemType_t dma_mem_type(void *addr)
 {
 	unsigned long addrVal = (unsigned long)addr;
 
-	if (addrVal >= VMALLOC_END) {
+	if (addrVal >= CONSISTENT_BASE) {
 		/* NOTE: DMA virtual memory space starts at 0xFFxxxxxx */
 
 		/* dma_alloc_xxx pages are physically and virtually contiguous */