XIF Invalid Compressed Instrs - Assert Slightly Wrong

Regarding this property: https://github.com/openhwgroup/core-v-verif/blob/master/lib/uvm_agents/uvma_cvxif/src/uvma_cvxif_assert.sv#L30 cvxif_assert.compressed_valid |-> cvxif_assert.compressed_req.instr[1:0] != 2'b11;

The assert seems to be based on an ambiguous part of the spec, and chosing the meaning not intended by spec. See https://github.com/openhwgroup/core-v-xif/issues/231