no-sse2 patch: Fix WebRTC aec3 module FTBFS
    
    The aec3 module attempts to do SSE2 runtime detection in a way that does
    not compile with GCC, so disable it. (SSE2 use in that module is now
    compile-time only, i.e., only enabled for the x86_64 package in Fedora.)
    
    The patch also optimizes x86_64 by making the SSE2 detection return a
    compile-time constant, which upstream neglected doing.