ARM: OMAP: Fix dmtimer init for omap1

We need to enable PM runtime on omap1 also as otherwise we
will get errors:

omap_timer omap_timer.1: omap_dm_timer_probe: pm_runtime_get_sync failed!
omap_timer: probe of omap_timer.1 failed with error -13
...

We are checking for OMAP_TIMER_NEEDS_RESET flag elsewhere so this is
safe to do.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>