vl/dri3: handle the case of different GPU(v4.2)

vl/dri3: handle the case of different GPU(v4.2)

In case of prime when rendering is done on GPU other then the
server GPU, use a seprate linear buffer for each back buffer
which will be displayed using present extension.

v2: Use a seprate linear buffer for each back buffer (Michel)
v3: Change variable names and fix coding style (Leo and Emil)
v4: Use PIPE_BIND_SAMPLER_VIEW for back buffer in case when
    a seprate linear buffer is used (Michel)
v4.1: remove empty line
v4.2: destroy the context and handle the case when
      create_context fails (Emil)

Signed-off-by: Nayan Deshmukh <nayan26deshmukh@gmail.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Acked-by: Michel Dänzer <michel.daenzer@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>