CHROMIUM: drm/exynos: fbdev: Offset is always zero

CHROMIUM: drm/exynos: fbdev: Offset is always zero

A freshly filled fb_info will always have .xoffset and .yoffset = 0.
So, computing an offset during during fbdev_update is not necessary,
since it is only called in the fbdev_probe/fbdev_create path.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
BUG=chromium-os:37097
TEST=compile test; manual check fbdev created and shows chromeball at boot

Change-Id: I648e16200cf3840a69e59a8f8d4dea69541c9cf7
Reviewed-on: https://gerrit.chromium.org/gerrit/39479
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Commit-Ready: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Daniel Kurtz <djkurtz@chromium.org>