[ARM] Orion: prepare for runtime-determined timer tick rate

Currently, orion5x uses a hardcoded timer tick rate of 166 MHz, but
the actual timer tick rate varies between different members of the SoC
family (and can vary based on strap pin settings).

This patch prepares for runtime determination of the timer tick rate.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
diff --git a/arch/arm/mach-orion5x/tsx09-common.c b/arch/arm/mach-orion5x/tsx09-common.c
index 83feac3..5128da1 100644
--- a/arch/arm/mach-orion5x/tsx09-common.c
+++ b/arch/arm/mach-orion5x/tsx09-common.c
@@ -16,6 +16,7 @@
 #include <linux/timex.h>
 #include <linux/serial_reg.h>
 #include "tsx09-common.h"
+#include "common.h"
 
 /*****************************************************************************
  * QNAP TS-x09 specific power off method via UART1-attached PIC
@@ -26,7 +27,7 @@
 void qnap_tsx09_power_off(void)
 {
 	/* 19200 baud divisor */
-	const unsigned divisor = ((ORION5X_TCLK + (8 * 19200)) / (16 * 19200));
+	const unsigned divisor = ((orion5x_tclk + (8 * 19200)) / (16 * 19200));
 
 	pr_info("%s: triggering power-off...\n", __func__);