sif: BZ4074: clean up the workaround

sif: BZ4074: clean up the workaround

Orabug: 23607042

This patch cleans up workaround 4074 in reviewing
the code while working on Orabug: 23607042.

1) This patch replaces the epsc_query_qp with reading
   the QPS from the memory directly.
   As the QP is already in RESET state,  accessing
   the QPS info from EPSC might potentially cause
   any unexpected returned data.
2) Remove the unused function sq_flush_wa4074.
3) For readibility, use the correct PSIF enum to
   mask PSIF specific WC code.

Signed-off-by: Wei Lin Guay <wei.lin.guay@oracle.com>
Reviewed-by: Knut Omang <knut.omang@oracle.com>