cmd: load: align cache flush

Prevent cache misalignment message by ensuring that a whole cache line
is flushed.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/cmd/load.c b/cmd/load.c
index 65557e4..77c3359 100644
--- a/cmd/load.c
+++ b/cmd/load.c
@@ -997,7 +997,7 @@
 	xyzModem_stream_terminate(false, &getcxmodem);
 
 
-	flush_cache(offset, size);
+	flush_cache(offset, ALIGN(size, ARCH_DMA_MINALIGN));
 
 	printf("## Total Size      = 0x%08x = %d Bytes\n", size, size);
 	setenv_hex("filesize", size);