feat: config.h for android arm64

[ElectroluxV2]

Please describe the changes this PR makes and why it should be merged:
Hi,
I was occurring an error during installation on termux on android:

make: Entering directory '/data/data/com.termux/files/home/ddbot/node_modules/@discordjs/opus/build' cc '-DNODE_GYP_MODULE_NAME=libopus' '-DUSING_UV_SHARED=1' '-DUSING_V8_SHARED=1' '-DV8_DEPRECATION_WARNINGS=1' '-DV8_DEPRECATION_WARNINGS' '-DV8_IMMINENT_DEPRECATION_WARNINGS' '-D_LARGEFILE_SOURCE' '-D_FILE_OFFSET_BITS=64' '-D__STDC_FORMAT_MACROS' '-DPIC' '-DHAVE_CONFIG_H' '-D_GLIBCXX_USE_C99_MATH' -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/include/node -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/src -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/deps/openssl/config -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/deps/openssl/openssl/include -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/deps/uv/include -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/deps/zlib -I/data/data/com.termux/files/home/.cache/node-gyp/14.14.0/deps/v8/include -I../deps/config/opus/android/arm64 -I../deps/opus/include -I../deps/opus/celt -I../deps/opus/silk -I../deps/opus/silk/float -fPIC -Wall -Wextra -Wno-unused-parameter -fvisibility=hidden -W -Wstrict-prototypes -Wall -Wextra -Wcast-align -Wnested-externs -Wshadow -Wno-parentheses -Wno-unused-parameter -Wno-sign-compare -Wno-maybe-uninitialized -O3 -fno-omit-frame-pointer -fPIC -MMD -MF ./Release/.deps/Release/obj.target/libopus/deps/opus/src/opus_multistream.o.d.raw -c -o Release/obj.target/libopus/deps/opus/src/opus_multistream.o ../deps/opus/src/opus_multistream.c warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean '-Wno-uninitialized'? [-Wunknown-warning-option] ../deps/opus/src/opus_multistream.c:29:10: fatal error: 'config.h' file not found #include "config.h" ^~~~~~~~~~ 1 warning and 1 error generated. make: *** [deps/libopus.target.mk:300: Release/obj.target/libopus/deps/opus/src/opus_multistream.o] Error 1 make: Leaving directory '/data/data/com.termux/files/home/ddbot/node_modules/@discordjs/opus/build' gyp ERR! build error gyp ERR! stack Error: `make` failed with exit code: 2 gyp ERR! stack at ChildProcess.onExit (/data/data/com.termux/files/usr/lib/node_modules/npm/node_modules/node-gyp/lib/build.js:194:23) gyp ERR! stack at ChildProcess.emit (events.js:315:20) gyp ERR! stack at Process.ChildProcess._handle.onexit (internal/child_process.js:277:12) gyp ERR! System Linux 4.4.205-perf+ gyp ERR! command "/data/data/com.termux/files/usr/bin/node" "/data/data/com.termux/files/usr/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "build" "--fallback-to-build" "--module=/data/data/com.termux/files/home/ddbot/node_modules/@discordjs/opus/prebuild/node-v83-napi-v3-android-arm64-unknown-unknown/opus.node" "--module_name=opus" "--module_path=/data/data/com.termux/files/home/ddbot/node_modules/@discordjs/opus/prebuild/node-v83-napi-v3-android-arm64-unknown-unknown" "--napi_version=7" "--node_abi_napi=napi" "--napi_build_version=3" "--node_napi_label=napi-v3" gyp ERR! cwd /data/data/com.termux/files/home/ddbot/node_modules/@discordjs/opus gyp ERR! node -v v14.14.0 gyp ERR! node-gyp -v v5.1.0 gyp ERR! not ok 

So I did copy android arm's config to arm64 folder, build flawlessly and more important works great, tested on One Plus 5.

Semantic versioning classification:

• This PR changes the library's interface (methods or parameters added)
• This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
• This PR only includes non-code changes, like changes to documentation, README, etc.
• None of above

[ElectroluxV2]

If someone would like to test it on its own I used this command to install:

npm install ElectroluxV2/opus#master 

[ElectroluxV2]

#41