rs: only emit pipe addresses which are really used

excerpt from cmd buffer generated by binary blob:
    0x08010581, /* LOAD_STATE (1) Base: 0x01604 Size: 1 Fixp: 0 */
    0x20000686, /*   [01604] RS.CONFIG := SOURCE_FORMAT=A8R8G8B8,DOWNSAMPLE_X=0,DOWNSAMPLE_Y=0,SOURCE_TILED=1,DEST_FORMAT=A8R8G8B8,DEST_TILED=0,SWAP_RB=1,FLIP=0 */
    0x08010583, /* LOAD_STATE (1) Base: 0x0160C Size: 1 Fixp: 0 */
    0xc0001c00, /*   [0160C] RS.SOURCE_STRIDE := STRIDE=0x1c00,MULTI=1,TILING=1 */
    0x08010585, /* LOAD_STATE (1) Base: 0x01614 Size: 1 Fixp: 0 */
    0x00000700, /*   [01614] RS.DEST_STRIDE := STRIDE=0x700,MULTI=0,TILING=0 */
    0x0802058c, /* LOAD_STATE (1) Base: 0x01630 Size: 2 Fixp: 0 */
    0xffffffff, /*   [01630] RS.DITHER[0] := 0xffffffff */
    0xffffffff, /*   [01634] RS.DITHER[1] := 0xffffffff */
    0x00000000, /* PAD */
    0x0801058f, /* LOAD_STATE (1) Base: 0x0163C Size: 1 Fixp: 0 */
    0x00000000, /*   [0163C] RS.CLEAR_CONTROL := BITS=0x0,MODE=DISABLED */
    0x080105a8, /* LOAD_STATE (1) Base: 0x016A0 Size: 1 Fixp: 0 */
    0x00000000, /*   [016A0] RS.EXTRA_CONFIG := AA=0x0,ENDIAN=NO_SWAP */
    0x080205b0, /* LOAD_STATE (1) Base: 0x016C0 Size: 2 Fixp: 0 */
    0x38910000, /*   [016C0] RS.PIPE[0].SOURCE_ADDR := ADDR_I */
    0x3894b000, /*   [016C4] RS.PIPE[1].SOURCE_ADDR := ADDR_27 */
    0x00000000, /* PAD */
    0x080105b8, /* LOAD_STATE (1) Base: 0x016E0 Size: 1 Fixp: 0 */
    0x38a37c00, /*   [016E0] RS.PIPE[0].DEST_ADDR := ADDR_P */
    0x08010588, /* LOAD_STATE (1) Base: 0x01620 Size: 1 Fixp: 0 */

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>