CHROMIUM: gpu: i915: Make RP down timeout shorter

CHROMIUM: gpu: i915: Make RP down timeout shorter

Make the GEN6_RP_DOWN_TIMEOUT significantly shorter -- from 1000000 to
10000. This helps save about 1W of power by keeping the GPU running at
lower frequency for longer.

BUG=none
TEST=playback a youtube video at 1080p and ensure there are no dropped
frames.

Change-Id: Id201a8eabdccad9e79fcc6383fdfc53e039300da
Signed-off-by: Sameer Nanda <snanda@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/30036
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>