drm/omap: increase DMM transaction timeout

drm/omap: increase DMM transaction timeout

The DMM driver uses a timeout of 1 ms to wait for DMM transaction to
finish. While DMM should always finish the operation within that time,
the timeout is rather strict. Small misbehavior of the system (e.g. an
irq taking too long) could trigger the timeout.

As the DMM is a critical piece of code for display memory management,
let's increase the timeout to 100 ms so that we are less likely to fail
a memory allocation in case of system misbehaviors. 100 ms is just a
guess of a reasonably large timeout. The HW should accomplish the task
in less than 1 ms.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>