Revert "Avoid use of deprecated high-bitdepth functions"

This reverts commit f9d77bd5a2541387dc435e052704b2e734307c20.

Reason for revert: 8x8 transform failures

BUG=https://bugs.chromium.org/p/aomedia/issues/detail?id=502

Change-Id: I2f6c10bc576a966bd5a878b7ee8389074bf45014
6 files changed