nios2: display altera sysid at startup

Display altera sysid at startup, which was once removed during
the move.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/arch/nios2/cpu/cpu.c b/arch/nios2/cpu/cpu.c
index f6d5cd3..be7f99c 100644
--- a/arch/nios2/cpu/cpu.c
+++ b/arch/nios2/cpu/cpu.c
@@ -21,6 +21,14 @@
 }
 #endif /* CONFIG_DISPLAY_CPUINFO */
 
+#ifdef CONFIG_ALTERA_SYSID
+int checkboard(void)
+{
+	display_sysid();
+	return 0;
+}
+#endif
+
 int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	disable_interrupts();