ARM: tegra: ardbeg: declare coherent memory

ARM: tegra: ardbeg: declare coherent memory

declare fixed or resizable coherent memory based
on kernel configuration.

bug 1445123

Change-Id: I43ad7889a18a7aa4db09895716a5af0d5bac455e
Signed-off-by: Vandana Salve <vsalve@nvidia.com>
Reviewed-on: http://git-master/r/362442
(cherry picked from commit d05f6c7ed23c81e90f96814ca0167207c6fdb680)
Reviewed-on: http://git-master/r/386276
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Krishna Reddy <vdumpa@nvidia.com>