ggml : fix avx512 const correctness

ggml-ci

Author: ggerganov

ggml.c

@@ -1058,7 +1058,7 @@ do {                                                                  \
 
 // unlike  _mm256_cvt intrinsics that require F16C, _mm512_cvt is defined in AVX512F
 // so F16C guard isn't required
-#define GGML_F32Cx16_LOAD(x)     _mm512_cvtph_ps(_mm256_loadu_si256((__m256i *)(x)))
+#define GGML_F32Cx16_LOAD(x)     _mm512_cvtph_ps(_mm256_loadu_si256((const __m256i *)(x)))
 #define GGML_F32Cx16_STORE(x, y) _mm256_storeu_si256((__m256i *)(x), _mm512_cvtps_ph(y, 0))
 
 #define GGML_F32Cx16_FMA(a, b, c) _mm512_fmadd_ps(b, c, a)