ARM: tegra: lp0 WAKE2 status clear

Tegra pmc WAKE2 status registers also need to be cleared
before re-entering lp0 mode.

Change-Id: I1bd5c48baf86ba23d0352594e97c360d363ce991
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-on: http://git-master/r/121185
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>