intel: give WAs some sanity

Give WAs descriptive names and document them in cmd.h.

As a future improvement, when

 INTEL_CMD_WA_GEN7_POST_COMMAND_CS_STALL
 INTEL_CMD_WA_GEN7_POST_COMMAND_DEPTH_STALL

are both set, it is possible to combine them into a PIPE_CONTROL.
diff --git a/icd/intel/pipeline.h b/icd/intel/pipeline.h
index cee5f49..d401027 100644
--- a/icd/intel/pipeline.h
+++ b/icd/intel/pipeline.h
@@ -118,12 +118,6 @@
 
 #define INTEL_PSO_CMD_ENTRIES   64
 
-enum {
-    GEN6_WA_POST_SYNC_FLUSH     = 1 << 0,
-    GEN6_WA_GEN7_VS_FLUSH       = 1 << 1,
-    GEN7_WA_MULTISAMPLE_FLUSH   = 1 << 2,
-};
-
 /**
  * 3D pipeline.
  */
@@ -211,8 +205,8 @@
         int PUSH_CONSTANT_BUFFER_size;
     } wm_state;
 
-    uint32_t pre_pso_wa_flags;
-    uint32_t post_pso_wa_flags;
+    uint32_t wa_flags;
+
     uint32_t cmds[INTEL_PSO_CMD_ENTRIES];
     XGL_UINT cmd_len;
 };