[mlir][ArmSME] Support 4-way widening outer products (#79288)

This patch introduces support for 4-way widening outer products. This
enables the fusion of 4 'arm_sme.outerproduct' operations that are
chained via the accumulator into single widened operations.

Changes:

- Adds the following operations:
  - smopa_4way, smops_4way
  - umopa_4way, umops_4way
  - sumopa_4way, sumops_4way
  - sumopa_4way, sumops_4way
- Implements conversions for the above ops to intrinsics in ArmSMEToLLVM.
- Extends 'arm-sme-outer-product' pass.

For a detailed description of these operations see the
'arm_sme.smopa_4way' description.