virtwl: Fix DMABuf support on when building for 32bit.
virtwl: Fix DMABuf support on when building for 32bit.

name/date/desc_len fields of drm_version struct are of type __kernel_size_t
and not unsigned long long.

BUG=chromium:837209
TEST=crosvm finds DRM device on kevin

Change-Id: If940b31cb730cbaa46ed781021cbe60189da9f65
Reviewed-on: https://chromium-review.googlesource.com/1064913
Commit-Ready: David Reveman <1dda8fffc4cb6d511b3f0060aad9cd12fd7f75f8@chromium.org>
Tested-by: David Reveman <1dda8fffc4cb6d511b3f0060aad9cd12fd7f75f8@chromium.org>
Reviewed-by: Zach Reizner <3374927928a53d04457674c546bd4de57c2044ec@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm