initial VCE support

[Christian König]

Hi everyone,

here is the next major code drop for the radeon driver. It adds support for
VCE2 as found on the newest CIK hardware generation. VCE1 as found on SI and
Trinity hardware generation is currently not supported, but might get added in
the future.

VCE is basically a hardware H264 encoding engine. It's optimized for low
latency encoding as found on wireless display, but can be used for general
purpose encoding as well.

The kernel patches implement everything needed to get the hardware block up and 
running. The mesa patches then implement a basic H264 encoder on top of that.
The support for encoding is currently exposed through the OpenMAX state 
tracker. Beside on the proper mailing lists the patches can be found here as
well:

Kernel: http://cgit.freedesktop.org/~deathsimple/linux/log/?h=vce-release
Mesa: http://cgit.freedesktop.org/~deathsimple/mesa/log/?h=vce-release

Additional to the new code a firmware file (BONAIRE_vce.bin) is needed which
can be found here: http://people.freedesktop.org/~agd5f/radeon_ucode/

Please review and as always comments are very welcome,
Christian.