fix OXGRF lib.c for arm

src/targets/ARCH/OXGRF/USERSPACE/LIB/oxgrf_lib.c

@@ -26,6 +26,10 @@
 #  include <immintrin.h>
 #endif
 
+#ifdef __aarch64__
+  #include <arm_neon.h>
+#endif
+
 //! Number of OXGRF devices
 int num_devices = 0;
 #ifdef __GNUC__
@@ -110,15 +114,15 @@ static int trx_oxgrf_write(openair0_device *device,openair0_timestamp timestamp,
         iq += 16;
         len -= 16;
     }
-#else
+#elif defined(__arm__) || defined(__aarch64__)
     __m128i a, *b;
     int len = nsamps * 2;
     int16_t *iq = buff[0];
 
     while (len >= 8) {
-        a = *(__m128i *)&iq[0];
-        b = (__m128i *)&iq[0];
-        *b = _mm_slli_epi16(a, 4);
+        a = *(int16x8_t *)&iq[0];
+        b = (int16x8_t *)&iq[0];
+        *b = vshlq_n_s16(a, 4);
         iq += 8;
         len -= 8;
     }