opus: bump from 1.1.2 to 1.1.4

1.1.3 brings performance optimizations on Android:
* Neon optimizations improving performance on ARMv7 and ARMv8 by up to 15%

1.1.4 fixes a potential security issue
* A specially-crafted Opus packet could cause an integer wrap-around in
the SILK LSF stabilization code. This would cause an out-of-bounds read
256 bytes before a constant table. In most circumstances, the
consequences are harmless and the result is simply noise in the audio.
This was reported as CVE-2017-0381.

Change-Id: If2c12ab5de12c420344735dc7ca89c2366a0045c