Unable to build for ARM

[tranzmatt]

I can't build for ARM based platforms. The default configure script sets up for x86 regardless of platform detected (and fails because it can't find xmmintrin.h), but if I enable neon, I get failures like this:

../../../src/dsp/convolve_neon.c:27:10: fatal error: openphy/convolve.h: No such file or directory
#include "openphy/convolve.h"
^~~~~~~~~~~~~~~~~~~~

[ftzdomino]

I was able to get this to build for ARM by downloading sse2neon.h from https://github.com/DLTcollab/sse2neon and applying the following diff:

diff --git a/src/dsp/convolve_sse.c b/src/dsp/convolve_sse.c
index fe5fe7a..39e04a9 100644
--- a/src/dsp/convolve_sse.c
+++ b/src/dsp/convolve_sse.c
@@ -18,11 +18,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

+#define _POSIX_C_SOURCE 200809L
 #include <string.h>
 #include <assert.h>
-#include <xmmintrin.h>
-#include <pmmintrin.h>
-#include <immintrin.h>
+
+#include <stdlib.h>
+#include "../sse2neon.h"
 #include <complex.h>

 #include <stdio.h>

Also, I had to add this to the Makefile for CFLAGS, CXXFLAGS, and CCASFLAGS:
-march=armv8-a+fp+simd+crypto+crc -D_POSIX_C_SOURCE=200112L