generate_gypi.sh: --disable-avx and --only-config flags

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 2a18a45e3e35a31b8943936abc3ed0fb747c74d3..ee10e99083eafdb26f99b14e10a67162cf126a2c 100644
--- a/source/config/linux/generic/vpx_config.c
+++ b/source/config/linux/generic/vpx_config.c
@@ -6,5 +6,5 @@
 /* in the file PATENTS.  All contributing project authors may */
 /* be found in the AUTHORS file in the root of the source tree. */
 #include "vpx/vpx_codec.h"
-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 --enable-vp9-postproc --size-limit=16384x16384";
+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 --enable-vp9-postproc --size-limit=16384x16384 --disable-avx --disable-avx2";
 const char *vpx_codec_build_config(void) {return cfg;}