[media] exynos4-is: Wait for 100us before opening sensor

Some user space use cases result in kernel hangup on the HIC_OPEN_SENSOR
command write. In case when a minimalistic application is used for setting
up the streaming, the hangups occur only occasionally. In case of GStreamer
use cases it is always the case.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>