r300: Use the defined values when writing to R300_SE_VTE_CNTL.

r300: Use the defined values when writing to R300_SE_VTE_CNTL.

You can verify this is correct with the following code.

  assert (0x043f ==
	  (R300_VTX_W0_FMT | R300_VPORT_X_SCALE_ENA | R300_VPORT_X_OFFSET_ENA
	   | R300_VPORT_Y_SCALE_ENA | R300_VPORT_Y_OFFSET_ENA |
	   R300_VPORT_Z_SCALE_ENA | R300_VPORT_Z_OFFSET_ENA));