Revert "revert "fbcon: Compare variable screen info instead of modes""

Revert "revert "fbcon: Compare variable screen info instead of modes""

This reverts commit fae8c6c89041afe14aca750b22d5eefcac591d25.
Xserver hang was observed due to the original change, hence reverted
as part of bug 1716596. The hang was root caused to bug 200169212, which
has been resolved by http://git-p4swmirror/r/16930. Hence restoring
the original change.

bug 200168814
bug 200169212

Change-Id: I402ea50b8e9e12b370469bda4e0d7e8123663cea
Signed-off-by: Naveen Kumar S <nkumars@nvidia.com>
Reviewed-on: http://git-master/r/1116012
(cherry picked from commit f78c0ce9e4190e72895b6c6cad6ecc8b2b5b0950)
Reviewed-on: http://git-master/r/1123702
GVS: Gerrit_Virtual_Submit
Reviewed-by: Winnie Hsu <whsu@nvidia.com>