Enable AVX2 optimizations in libvpx

source/config/linux/generic/vpx_config.c

Index: source/config/linux/generic/vpx_config.c
diff --git a/source/config/linux/generic/vpx_config.c b/source/config/linux/generic/vpx_config.c
index 36640a4b5245442c823c7828964a167f2baff702..176ed868f231bb8054a793d94f46c857d1fe94e7 100644
--- a/source/config/linux/generic/vpx_config.c
+++ b/source/config/linux/generic/vpx_config.c
@@ -5,5 +5,5 @@
 /* tree. An additional intellectual property rights grant can be found */
 /* in the file PATENTS.  All contributing project authors may */
 /* be found in the AUTHORS file in the root of the source tree. */
-static const char* const cfg = "--target=generic-gnu --enable-pic --enable-realtime-only --enable-external-build --enable-postproc --disable-install-srcs --enable-multi-res-encoding --enable-temporal-denoising --disable-unit-tests --disable-install-docs --disable-examples --disable-avx2 --enable-vp9-temporal-denoising";
+static const char* const cfg = "--target=generic-gnu --enable-pic --enable-realtime-only --enable-external-build --enable-postproc --disable-install-srcs --enable-multi-res-encoding --enable-temporal-denoising --disable-unit-tests --disable-install-docs --disable-examples --enable-vp9-temporal-denoising";
 const char *vpx_codec_build_config(void) {return cfg;}