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/copyright

@@ -9,6 +9,7 @@ Files-Excluded:
  deps/lzma/*
  deps/libcaption/*
  plugins/obs-qsv11/*
+ libobs/util/simde/*
 
 Files: *
 Copyright: 2013-2017, Hugh Bailey <obs.jim@gmail.com>
@@ -87,24 +88,6 @@ Copyright: 1998, Ben Elliston
            1998-2001, Ross Johnson
 License: LGPL-2.1+
 
-Files: libobs/util/simde/*
-Copyright: 2017-2018, Evan Nemerson <evan@nemerson.com>
-           2015-2017, John W. Ratcliff <jratcliffscarab@gmail.com>
-           2015, Brandon Rowlett <browlett@nvidia.com>
-           2015, Ken Fast <kfast@gdeb.com>
-           2017, Hasindu Gamaarachchi <hasindu@unsw.edu.au>
-           2018, Jeff Daily <jeff.daily@amd.com>
-License: Expat
-
-Files: libobs/util/simde/check.h
-       libobs/util/simde/hedley.h
-       libobs/util/simde/simde-arch.h
-       libobs/util/simde/simde-common.h
-Copyright: 2017-2018, Evan Nemerson <evan@nemerson.com>
-License: CC0-1.0
- On Debian systems, the complete text of the Creative Commons 1.0 Universal
- License can be found in "/usr/share/common-licenses/CC0-1.0".
-
 Files: plugins/decklink/linux/decklink-sdk/*
        plugins/decklink/mac/decklink-sdk/*
        plugins/decklink/win/decklink-sdk/*