ARM: OMAP2+: Display correct system timer name

Currently on boot, when displaying the name of the gptimer used for
clockevents and clocksource timers, the timer ID is shown. However,
when booting with device-tree, the timer ID is not used to select a
gptimer but a timer property. Hence, it is possible that the timer
selected when booting with device-tree does not match the ID shown.
Therefore, instead display the HWMOD name of the gptimer and use
the HWMOD name as the name of clockevent and clocksource timer (if a
gptimer is used).

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>