ARM: OMAP3: Update clocksource timer selection

When booting with device-tree for OMAP3 and AM335x devices and a gptimer
is used as the clocksource (which is always the case for AM335x), a
gptimer located in a power domain that is not always-on is selected.
Ideally we should use a gptimer for clocksource that is located in a
power domain that is always on (such as the wake-up domain) so that time
can be maintained during a kernel suspend without keeping on additional
power domains unnecessarily.

In order to fix this so that we can select a gptimer located in a power
domain that is always-on, the following changes were made ...
1. Currently, only when selecting a gptimer to use for a clockevent
   timer, do we pass a timer property that can be used to select a
   specific gptimer. Change this so that we can pass a property when
   selecting a gptimer to use for a clocksource timer too.
2. Currently, when selecting either a gptimer to use for a clockevent
   timer or a clocksource timer and no timer property is passed, then
   the first available timer is selected regardless of the properties
   it has. Change this so that if no properties are passed, then a timer
   that does not have additional features (such as always-on, dsp-irq,
   pwm, and secure) is selected.

For OMAP3 and AM335x devices that use a gptimer for clocksource, change
the selection of the gptimer so that by default the gptimer located in
the always-on power domain is used for clocksource instead of
clockevents.

Please note that using a gptimer for both clocksource and clockevents
can have a system power impact during idle. The reason being is that
OMAP and AMxxx devices typically only have one gptimer in a power domain
that is always-on. Therefore when the kernel is idle both the clocksource
and clockevent timers will be active and this will keep additional power
domains on. During kernel suspend, only the clocksource timer is active
and therefore, it is better to use a gptimer in a power domain that is
always-on for clocksource.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
ARM: OMAP2+: Store ID of system timers in timer structure

Currently, the timer ID is being passed to the function
omap_dm_timer_init_one(). Instead of passing the ID separately, store it
in the omap_dm_timer structure, that is also passed, and access the ID
from this structure.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
ARM: OMAP4+: Fix sparse warning in system timers

Commit 6bb27d7 (ARM: delete struct sys_timer) changed the function
created by the macro OMAP_SYS_32K_TIMER_INIT from static void to void.
For OMAP4+ devices this created the following sparse warning ...

arch/arm/mach-omap2/timer.c:585:1: warning: symbol
	'omap4_sync32k_timer_init' was not declared. Should it be static?

The function omap4_sync32k_timer_init() is not referenced outside of the
file timer.c and so make this function static.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>