[Intel-gfx] [RFC i-g-t 2/6] tests/gem_pwrite: drop stolen memory related subtests

[Chris Wilson]

Quoting Daniele Ceraolo Spurio (2017-10-03 00:00:14)
> The feature was never merged and there has been no progress in the
> last year. The subtests are currently skipping on all platforms by
> checking a field in the get_aperture ioctl structure that doesn't
> exist in the kernel version of the struct.

Again, more kernel code not being covered by tests...
-Chris