r300: Use the defined values when writing to R300_VAP_INPUT_CNTL_[01].

r300: Use the defined values when writing to R300_VAP_INPUT_CNTL_[01].

You can verify this is correct with the following code.

  assert (0x00000001 == R300_INPUT_CNTL_0_COLOR);

  assert (0x00000405 ==
	  (R300_INPUT_CNTL_POS | R300_INPUT_CNTL_COLOR |
	   R300_INPUT_CNTL_TC0));