#486 MESA_ycbcr not working correctly with radeon (M9000)

[Stefan Brüns]

Trying to use YUV on Radeon Mobility 9000 results in the right
texture with wrong colors.

Seems like the color components dont get calculated correctly, the
colors are the same as one would set Y=G;Cb=B;Cr=R. Or written
in Matrix form:

|R| | 0 0 1 | | Y |
|G| = | 1 0 0 | * | Cb |
|B| | 0 1 0 | | Cr |

Correct Matrix would be

| 1.00 0.00 1.40 |
| 1.00 -.34 -.71 |
| 1.00 1.77 0.00 |

Seems to be a bug in the radeon driver, mga and mesasoft work.

Tested with the MESA yuvrect and yuvsquare examples.