mmq: add assert for size

Author: Aman Gupta

ggml/src/ggml-cuda/mmq.cuh

@@ -52,6 +52,7 @@ struct block_fp4_mmq {
 
 static_assert(sizeof(block_q8_1_mmq) == 4*QK8_1 + 4*sizeof(half2), "Unexpected block_q8_1_mmq size");
 static_assert(sizeof(block_q8_1_mmq) == 4*sizeof(block_q8_1),      "Unexpected block_q8_1_mmq size");
+static_assert(sizeof(block_fp4_mmq)  == 72, "Unexpected block_fp4_mmq size");
 
 static mmq_q8_1_ds_layout mmq_get_q8_1_ds_layout(const ggml_type type_x) {
     switch (type_x) {