nios2: implement get_ticks and get_tbclk

* Copy over Blackfin's get_ticks and get_tbclk - they work just fine on
   Nios2.

Signed-off-by: Alex Hornung <alex@alexhornung.com>
Signed-off-by: Thomas Chou <thomas@wytron.com.tw>

arch/nios2/cpu/interrupts.c

@@ -98,6 +98,27 @@ ulong get_timer (ulong base)
 	return (timestamp - base);
 }
 
+/*
+ * This function is derived from Blackfin code (read timebase as long long).
+ * On Nios2 it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+	return get_timer(0);
+}
+
+/*
+ * This function is derived from Blackfin code.
+ * On Nios2 it returns the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+	ulong tbclk;
+
+	tbclk = CONFIG_SYS_HZ;
+	return tbclk;
+}
+
 /* The board must handle this interrupt if a timer is not
  * provided.
  */