Support mxfp4 for GPT-OSS (#8843)

Co-authored-by: Co-author fzyzcjy <ch271828n@outlook.com>
Co-authored-by: fzyzcjy <5236035+fzyzcjy@users.noreply.github.com>
Co-authored-by: zhuofan1123 <zhuofanl@nvidia.com>
Co-authored-by: liz-badada <jinyanc@nvidia.com>
Co-authored-by: xutizhou <xutingz@nvidia.com>
Co-authored-by: linhu-nv <linhu@nvidia.com>

python/sglang/srt/utils.py

@@ -2124,6 +2124,10 @@ def next_power_of_2(n: int):
     return 1 << (n - 1).bit_length() if n > 0 else 1
 
 
+def round_up(x: int, y: int) -> int:
+    return ((x - 1) // y + 1) * y
+
+
 setattr(triton, "next_power_of_2", next_power_of_2)