Disable upsampled references for best and realtime quality deadline

- For resolution > 1080p, this CL also disables upsampled
  references for best and realtime quality deadline besides
  good quality deadline.
  The following CL only disabled the good quality deadline:
  https://chromium-review.googlesource.com/#/c/405761/

- The issue was found by a segmentation fault happened in 4K
  --best mode encoding test. Current CL fixes the encoder
  segmentation fault temporarily.

- Another bug is filed:
  https://bugs.chromium.org/p/aomedia/issues/detail?id=108
  to track down the segmentation fault.

BUG=aomedia:107

Change-Id: I6f4bf14762b8e92d7b501d752167414cf37a6b26
1 file changed