[mlir] add memref dialect as dependent of lower-affine pass

The lower-affine pass also processes affine load and store operations
that get converted to load and store operations now available in the
memref dialect. Since it produces operations from the memref dialect,
this dialect should be registered as dependent for this pass. It is rare
but possible to have code that doesn't have memref operations in the
input and calls this pass.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D99720