CONFIG_OMAP_32K_TIMER is kind of standing on the single zImage way.
Make OMAP2+ timer code independant from the CONFIG_OMAP_32K_TIMER
setting.
To remove the dependancy, several conversions/additions had to be done:
1) Timer initialization functions are named by the platform
   name and the clock source in use.
   This also makes it possible to define and use the GPTIMER as the
   clock source instead of the 32K timer on platforms that do not have
   the 32K timer ip block or the 32K timer is not wired on the board.
   Currently, the the timer is chosen in the machine_desc structure on
   per board basis. Later, DT should be used to choose the timer.
2) Settings under the CONFIG_OMAP_32K_TIMER option are used as defaults
   and those under !CONFIG_OMAP_32K_TIMER are removed.
   This removes the CONFIG_OMAP_32K_TIMER on OMAP2+ timer code.
3) Since we have all the timers defined inside machine_desc structure
   and we no longer need the fallback to gp_timer clock source in case
   32k_timer clock source is unavailable (namely on AM33xx), we no
   longer need the #ifdef around omap2_sync32k_clocksource_init()
   function. Remove the #ifdef CONFIG_OMAP_32K_TIMER around the
   omap2_sync32k_clocksource_init() function.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Cc: Jon Hunter <jon-hunter@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Jon Hunter <jon-hunter@ti.com>