use the packaged libsimde-dev

* debian/patches:
   - Use the SIMD Everywhere headers from libsimde-dev, instead of upstream's
     code copy
* debian/control
   - Build-dep on libsimde-dev
   - Add "Built-Using: ${simde:Built-Using}" to all the binary packages to
     document the version of libsimde-dev used, as required to keep that
     version in the Debian archive, which is needed to fulfill the GPL
* debian/copyright:
   - exclude libobs/util/simde/* as we will use the files from libsimde-dev
* debian/rules:
   - Include the recommended flags for SIMDe, especially important for
     non-X86 architectures

debian/control

@@ -29,6 +29,7 @@ Build-Depends:
  libpulse-dev,
  libqt5svg5-dev,
  libqt5x11extras5-dev,
+ libsimde-dev,
  libspeexdsp-dev,
  libswresample-dev,
  libswscale-dev,
@@ -58,6 +59,7 @@ Rules-Requires-Root: no
 
 Package: obs-studio
 Architecture: any
+Built-Using: ${simde:Built-Using}
 Depends: obs-plugins (= ${binary:Version}), ${misc:Depends}, ${shlibs:Depends}, ${python3:Depends}
 Description: recorder and streamer for live video content
  OBS Studio is designed for efficiently recording and streaming live video
@@ -74,6 +76,7 @@ Description: recorder and streamer for live video content
 
 Package: obs-plugins
 Architecture: any
+Built-Using: ${simde:Built-Using}
 Depends: ${misc:Depends}, ${shlibs:Depends}, ${python3:Depends}
 Recommends: vlc
 Description: recorder and streamer for live video content (plugins)
@@ -86,6 +89,7 @@ Package: libobs0
 Multi-Arch: same
 Section: libs
 Architecture: any
+Built-Using: ${simde:Built-Using}
 Depends: ${misc:Depends}, ${shlibs:Depends}
 Description: recorder and streamer for live video content (shared library)
  OBS Studio is designed for efficiently recording and streaming live video
@@ -96,6 +100,7 @@ Description: recorder and streamer for live video content (shared library)
 Package: libobs-dev
 Section: libdevel
 Architecture: any
+Built-Using: ${simde:Built-Using}
 Depends:
  libobs0 (= ${binary:Version}),
  ${misc:Depends}