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>

arch/arm/kernel/time.c

@@ -30,11 +30,6 @@
 #include <asm/mach/arch.h>
 #include <asm/mach/time.h>
 
-/*
- * Our system timer.
- */
-static struct sys_timer *system_timer;
-
 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
     defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
 /* this needs a better home */
@@ -120,8 +115,6 @@ int __init register_persistent_clock(clock_access_fn read_boot,
 
 void __init time_init(void)
 {
-	system_timer = machine_desc->timer;
-	system_timer->init();
+	machine_desc->init_time();
 	sched_clock_postinit();
 }
-