Revert "radeon/winsys: pad IBs to a multiple of 8 DWs"

This reverts commit 4a8d1c5ef2f9c57a3c2feb829be3534ac43b9077.

This commit causes compilation failures ("'SI' undeclared"), which,
embarrassingly enough, I failed to notice earlier.
diff --git a/src/gallium/winsys/radeon/drm/radeon_drm_cs.c b/src/gallium/winsys/radeon/drm/radeon_drm_cs.c
index 007d129..6a7115b 100644
--- a/src/gallium/winsys/radeon/drm/radeon_drm_cs.c
+++ b/src/gallium/winsys/radeon/drm/radeon_drm_cs.c
@@ -455,36 +455,6 @@
     struct radeon_drm_cs *cs = radeon_drm_cs(rcs);
     struct radeon_cs_context *tmp;
 
-    switch (cs->base.ring_type) {
-    case RING_DMA:
-	    /* pad DMA ring to 8 DWs */
-	    if (cs->ws->info.chip_class <= SI) {
-		    while (rcs->cdw & 7)
-			    OUT_CS(&cs->base, 0xf0000000); /* NOP packet */
-	    } else {
-		    while (rcs->cdw & 7)
-			    OUT_CS(&cs->base, 0x00000000); /* NOP packet */
-	    }
-	    break;
-    case RING_GFX:
-	    /* pad DMA ring to 8 DWs to meet CP fetch alignment requirements
-	     * r6xx, requires at least 4 dw alignment to avoid a hw bug.
-	     */
-            if (flags & RADEON_FLUSH_COMPUTE) {
-		    if (cs->ws->info.chip_class <= SI) {
-			    while (rcs->cdw & 7)
-				    OUT_CS(&cs->base, 0x80000000); /* type2 nop packet */
-		    } else {
-			    while (rcs->cdw & 7)
-				    OUT_CS(&cs->base, 0xffff1000); /* type3 nop packet */
-		    }
-	    } else {
-		    while (rcs->cdw & 7)
-			    OUT_CS(&cs->base, 0x80000000); /* type2 nop packet */
-	    }
-	    break;
-    }
-
     if (rcs->cdw > RADEON_MAX_CMDBUF_DWORDS) {
        fprintf(stderr, "radeon: command stream overflowed\n");
     }