drv: remove unused #include <linux/dma-buf.h>

A leftover from prior refactor. Unnecessary and broke android builds.

Fixes: 3ab89b0 ("xe: add initial Xe kmd support for gen12 xelp")

BUG=b:358427077
TEST=Builds + CQ

Change-Id: I7ed2317409c2c381a244d714a26201662151adfd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/6250261
Commit-Queue: Ryan Neph <ryanneph@google.com>
Reviewed-by: Matt Turner <msturner@google.com>
Auto-Submit: Ryan Neph <ryanneph@google.com>
Commit-Queue: Matt Turner <msturner@google.com>
Tested-by: Ryan Neph <ryanneph@google.com>