iris: Flag fewer dirty bits in BLORP

v2: Skip flagging IRIS_DIRTY_DEPTH_BUFFER if
    BLORP_BATCH_NO_EMIT_DEPTH_STENCIL is set (Kenneth Graunke)

Signed-off-by: Sagar Ghuge <sagar.ghuge@intel.com>
24 jobs for !11 with blorp in 49 minutes and 11 seconds (queued for 18 seconds)
merge request