Do not try to load hybrid driver on unsupported platforms

[rathann]

Currently, the intel driver tries to load hybrid_drv_video.so in each case. On IVB and older machines, it doesn't make sense to have it installed as they're not supported. When it's not installed, intel driver complains:

$ vainfo
libva info: VA-API version 1.9.0
libva info: User environment variable requested driver 'i965'
libva info: Trying to open /usr/lib64/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_1_8
failed to open /usr/lib64/dri/hybrid_drv_video.so
Not using hybrid_drv_video.so
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.9 (libva 2.9.0)
vainfo: Driver version: Intel i965 driver for Intel(R) Ivybridge Desktop - 2.4.1
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            :	VAEntrypointVLD
      VAProfileMPEG2Simple            :	VAEntrypointEncSlice
      VAProfileMPEG2Main              :	VAEntrypointVLD
      VAProfileMPEG2Main              :	VAEntrypointEncSlice
      VAProfileH264ConstrainedBaseline:	VAEntrypointVLD
      VAProfileH264ConstrainedBaseline:	VAEntrypointEncSlice
      VAProfileH264Main               :	VAEntrypointVLD
      VAProfileH264Main               :	VAEntrypointEncSlice
      VAProfileH264High               :	VAEntrypointVLD
      VAProfileH264High               :	VAEntrypointEncSlice
      VAProfileH264StereoHigh         :	VAEntrypointVLD
      VAProfileVC1Simple              :	VAEntrypointVLD
      VAProfileVC1Main                :	VAEntrypointVLD
      VAProfileVC1Advanced            :	VAEntrypointVLD
      VAProfileNone                   :	VAEntrypointVideoProc
      VAProfileJPEGBaseline           :	VAEntrypointVLD

While having it installed doesn't hurt, I would prefer not to waste even 5MB of storage space (for cmrt and libva-intel-hybrid-driver) just to shut up a useless warning message.