intel/blorp: Drop clear color assignment prior to Xe2

This hasn't been used since the responsibility of clear color updates
moved to the drivers.

Reviewed-by: Rohan Garg <rohan.garg@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33776>

src/intel/blorp/blorp_clear.c

@@ -519,12 +519,6 @@ blorp_fast_clear(struct blorp_batch *batch,
    else
       params.op = BLORP_OP_MCS_COLOR_CLEAR;
 
-   /* If a swizzle was provided, we need to swizzle the clear color so that
-    * the hardware color format conversion will work properly.
-    */
-   params.dst.clear_color =
-      isl_color_value_swizzle_inv(params.dst.clear_color, swizzle);
-
    batch->blorp->exec(batch, &params);
 }