Switch GM20b GPCPLL under bypass when changing post-divider setting
(for now, don't assume that post-divider is glitch-less).
Change-Id: I62b1285c035de0913207a86c41f37b7765da3893
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/495300
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bo Yan <byan@nvidia.com>