leon: implement missing get_tbclk()

Without this patch SPARC/LEON does not build.

Reported-by: Tom Rini <trini@ti.com>
Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>

arch/sparc/cpu/leon2/cpu_init.c

@@ -110,6 +110,11 @@ int timer_interrupt_init_cpu(void)
 	return LEON2_TIMER1_IRQNO;
 }
 
+ulong get_tbclk(void)
+{
+	return TIMER_BASE_CLK;
+}
+
 /*
  * This function is intended for SHORT delays only.
  */

arch/sparc/cpu/leon3/cpu_init.c

@@ -222,6 +222,11 @@ int timer_interrupt_init_cpu(void)
 	return gptimer_irq;
 }
 
+ulong get_tbclk(void)
+{
+	return TIMER_BASE_CLK;
+}
+
 /*
  * This function is intended for SHORT delays only.
  */