USB: Align buffers at cacheline

This avoids cache-alignment warnings shown in console
when a usb command is entered.

Whenever X bytes of unaligned buffer is invalidated, arm core
invalidates X + Y bytes as per the cache line size and throws
these warnings.

Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/common/cmd_usb.c b/common/cmd_usb.c
index 9eba271..a8e3ae5 100644
--- a/common/cmd_usb.c
+++ b/common/cmd_usb.c
@@ -150,7 +150,8 @@
 
 void usb_display_string(struct usb_device *dev, int index)
 {
-	char buffer[256];
+	ALLOC_CACHE_ALIGN_BUFFER(char, buffer, 256);
+
 	if (index != 0) {
 		if (usb_string(dev, index, &buffer[0], 256) > 0)
 			printf("String: \"%s\"", buffer);