lpcnetfreedv: fix darwin build

diff --git a/CMakeLists.txt b/CMakeLists.txt

index 1600871..1536c55 100644

--- a/CMakeLists.txt

+++ b/CMakeLists.txt

@@ -158,7 +158,7 @@ elseif(${SSE} AND (${SSE_PRESENT} OR ${SSE_PRESENT} GREATER 0))

 # AVX and AVX2 machines will also match on SSE

     message(STATUS "sse processor flags found or enabled.")

     set(LPCNET_C_PROC_FLAGS -msse4.1)

-elseif(${NEON} AND (${NEON_PRESENT} OR ${NEON_PRESENT} GREATER 0))

+elseif(${NEON} AND (${NEON_PRESENT} OR ${NEON_PRESENT} GREATER 0) AND NOT APPLE)

     # RPi / ARM 32bit

     message(STATUS "neon processor flags found or enabled.")

     set(LPCNET_C_PROC_FLAGS -mfpu=neon -march=armv8-a -mtune=cortex-a53)

  nativeBuildInputs = [ cmake ];

  patches = [

    # extracted from https://github.com/drowe67/LPCNet/pull/59

    ./darwin.patch

  ];

  postPatch = ''

    mkdir build

    ln -s ${data} build/lpcnet_${dataVersion}.tgz