pan/bi: Set eldest_colour dependency for ST_TILE

I don't think we'll ever hit this in practice, since it's not needed for
blend shaders, but better to correct the code anyway.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12478>

src/panfrost/bifrost/bi_schedule.c

@@ -1634,6 +1634,7 @@ bi_schedule_clause(bi_context *ctx, bi_block *block, struct bi_worklist st, uint
                                 clause->dependencies |= (1 << BIFROST_SLOT_ELDEST_DEPTH);
                                 break;
                         case BI_OPCODE_LD_TILE:
+                        case BI_OPCODE_ST_TILE:
                                 if (!ctx->inputs->is_blend)
                                         clause->dependencies |= (1 << BIFROST_SLOT_ELDEST_COLOUR);
                                 break;