ARM: delete struct sys_timer

Now that the only field in struct sys_timer is .init, delete the struct,
and replace the machine descriptor .timer field with the initialization
function itself.

This will enable moving timer drivers into drivers/clocksource without
having to place a public prototype of each struct sys_timer object into
include/linux; the intent is to create a single of_clocksource_init()
function that determines which timer driver to initialize by scanning
the device dtree, much like the proposed irqchip_init() at:
http://www.spinics.net/lists/arm-kernel/msg203686.html

Includes mach-omap2 fixes from Igor Grinberg.

Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

drivers/clocksource/sunxi_timer.c

@@ -104,7 +104,7 @@ static struct of_device_id sunxi_timer_dt_ids[] = {
 	{ }
 };
 
-static void __init sunxi_timer_init(void)
+void __init sunxi_timer_init(void)
 {
 	struct device_node *node;
 	unsigned long rate = 0;
@@ -165,7 +165,3 @@ static void __init sunxi_timer_init(void)
 
 	clockevents_register_device(&sunxi_clockevent);
 }
-
-struct sys_timer sunxi_timer = {
-	.init = sunxi_timer_init,
-};