AT91 Fix: return value of get_tbclk

* Fix: return value of get_tbclk
 * this fixes issue with prematurely restart/retry, if BOOT_RETRY_TIMEOUT is used

Signed-off-by: Jens Scharsig <js_at_ng@scharsoft.de>

arch/arm/cpu/arm926ejs/at91/timer.c

@@ -138,8 +138,5 @@ ulong get_timer(ulong base)
  */
 ulong get_tbclk(void)
 {
-	ulong tbclk;
-
-	tbclk = CONFIG_SYS_HZ;
-	return tbclk;
+	return timer_freq;
 }