Buddy Gemmini: IR dumps for matmul + batch_matmul + conv

[101sparsh]

This PR adds reproducible Gemmini lowering experiments (inputs + --mlir-print-ir-after-all logs).

What’s included:

• experiments/gemmini/inputs: matmul.mlir + buddy examples (batch_matmul, conv_2d_nchw_fchw_f32)
• experiments/gemmini/logs: IR dumps showing linalg -> gemmini.tile_* -> gemmini.intr.* + LLVM dialect

How to reproduce:
buddy-opt <input.mlir> --convert-linalg-to-gemmini --lower-gemmini --mlir-print-ir-after-all 2>

Notes:

• matmul shows gemmini.tile_matmul + gemmini.intr.loop_ws/config/flush
• conv shows gemmini.intr.loop_conv_ws_config* + loop_conv_ws + flush