arm: omap2+: omap_device: remove no_idle_on_suspend

Remove "no_idle_on_suspend" check, since respective
driver should be able to prevent idling of an
omap device whenever required.

Driver's can get same behavior by just returning -EBUSY
from their ->runtime_suspend only during suspend.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Rajendra nayak <rnayak@ti.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>