BACKPORT: drm: Protect fb_defio in drivers with CONFIG_KMS_FBDEV_EMULATION

For reasons that entirely elude me fb.h exposes all the structures,
even when it is not enabled. Except for special stuff like fb_defio.

Which means all the drivers which haven't yet switched over to the
defio support in the helpers and still roll their own, will fail
to compile when fbdev emulation is disabled. Protect just those
bits, as a gnarly reminder that conversion to the core defio helpers
would be good.

BUG=b:117899525
TEST=trybot

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470847958-28465-6-git-send-email-daniel.vetter@ffwll.ch
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit 2b721f20770ccbca4d3dad58e1bd44aa570efb3f)
Signed-off-by: Stphane Marchesin <marcheu@chromium.org>
[marcheu: fixed extra udl_fb uses of fb_defio]
Signed-off-by: Pohsien Wang <pwang@chromium.org>

Change-Id: I66f5d35ed74ec1844bf5e26ecb626468f61370d6
Reviewed-on: https://chromium-review.googlesource.com/1446243
Commit-Ready: Po-Hsien Wang <pwang@chromium.org>
Tested-by: Po-Hsien Wang <pwang@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
2 files changed