disable unused parameter warning
disable unused parameter warning

cpuid, scale_neon, planarfunctions and jpeg have internal API's
with specialized versions that do not use all parameters.
Disable the warning in Android.mk for now.

BUG=libyuv:681
TEST=android make builds without warning.

Change-Id: I72ee654c376c6dd85b616fc4438e3ad0a86b39bc
Reviewed-on: https://chromium-review.googlesource.com/440510
Commit-Queue: Frank Barchard <52415189a3f67d375195cbbb6fdb1f1759498e57@google.com>
Reviewed-by: Henrik Kjellander <60c11d3e646624f25a02b88f51d51ca6b7ff7c72@chromium.org>

lemenkov/libyuv,lemenkov/libyuv,lemenkov/libyuv,lemenkov/libyuv