a few more configs for 2d grids (#2649)

Added two nice grid configs for the 2d pointwise kernel cases for WRT5
workload.
Confirmed that they were picked up when using max autotune.

(cherry picked from commit f1eac49)
(cherry picked from commit 2e79001)

Author: AmdSampsa

torch/_inductor/runtime/triton_heuristics.py

@@ -2601,6 +2601,8 @@ def pointwise(
                 triton_config_with_settings(size_hints, 64, 64),  # ~8% better for fp16
                 triton_config_with_settings(size_hints, 256, 16),
                 triton_config_with_settings(size_hints, 16, 256),
+                triton_config_with_settings(size_hints, 128, 16), # wrt: +10% for some kernels
+                triton_config_with_settings(size_hints, 32, 512), # wrt: +30% for some kernels
                 triton_config_with_settings(size_hints, bs, 1),
                 triton_config_with_settings(size_hints, 1, bs),
                 *hinted_configs,