arc: devboards: Implement checkboard()

This allows us to print nice board name on boot.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/board/synopsys/hsdk/hsdk.c b/board/synopsys/hsdk/hsdk.c
index ff34359..8a2c201 100644
--- a/board/synopsys/hsdk/hsdk.c
+++ b/board/synopsys/hsdk/hsdk.c
@@ -1053,3 +1053,9 @@
 
 	return 0;
 }
+
+int checkboard(void)
+{
+	puts("Board: Synopsys ARC HS Development Kit\n");
+	return 0;
+};