csr_wr_in_wb_flush_i seems not to be fully functional

Created by: Silabs-ArjanB

csr_wr_in_wb_flush_i is supposed to make sure that the CSRs are updated after which the pipeline is flushed and the new settings are used. This 'after which' part seems not to have been implemented. I expect that for example updated PMP settings will not affect the next instruction as they should. (Should be easy to see in formal or with a directed test)