[Encode] Enable pro-video fixed-function encode on Linux VA-API

* [Encode] Enable pro-video fixed-function encode on Linux VA-API
Add net-new pro-video all-intra encode support on the Linux VA-API
path and bring up the target platform so the codec is advertised and
runs end-to-end.
- New VA-API encode DDI that translates VA <-> HAL and forwards to the
  shared encode pipeline; factory-registered for the pro-video encode
  profile and slice entrypoint. The DDI is a thin translator with no
  re-implemented encode logic and no frame-header regeneration.
- New encode capability table for the target platform revision
  (RT-format, max width/height, rate control, packed-header caps),
  gated to that platform. Encode caps are moved out of the previous
  platform's table, which now retains decode support only.
- user feature the target device id to its platform id in the Linux
  sysinfo and SKU/WA setup, so the platform is brought up and the
  encode profile is advertised (previously it was never enabled on
  Linux, so config/context creation failed).
- user feature PRE_PATCHED patch-list entries at every encode
  address-write site in the media pipeline command implementation, so
  Linux resolves resource addresses correctly.
- Skip patch-list registration when the OS provides no patch hooks,
  so mock-OS command code-gen unit tests treat a missing patch list as
  "nothing to register" and succeed; Linux (which always supplies the
  hooks) is unchanged.
- Map Media_Format_YUY2 to GMM_FORMAT_YUY2_2x1 (32bpp 2x1 packed 4:2:2)
  so a linear YUY2 surface gets the tighter render pitch matching the
  reference implementation; tiled YUY2 and sibling packed formats are
  unchanged.
- Enable the Linux build wiring for the encode feature and update the
  proprietary DRM mock to present the target device id for platform
  resolution under unit test.
Keep the open source tree free of net-new encode code: the
UseNextEncodePipeline() bridge and the linear-surface path use
_MEDIA_RESERVED include-hooks with the implementation fragments in the
restricted DDI tree; linear surfaces are requested from the app via a
VA external buffer descriptor rather than reserved DDI hooks. The
shared encode/decode caps-includes aggregator is relocated to a
common/ ddi directory. Net open-tree diff vs upstream is only the
guard scaffolding.
Why: the codec's fixed-function encode was previously unavailable on
Linux and the target platform was never brought up, so the encode
profile was unadvertised and initialization failed. These changes
complete the Linux enablement so the encode produces command buffers
matching the validated CI-Daily reference.
Verified: release-internal build (defines _MEDIA_RESERVED) is clean;
all 45 media ULTs pass; command-buffer equivalence suites
8396002/3/4 pass.