msm: mdss: mdp: do null commit during panel reconfiguration

If panel reconfiguration is triggered during splash handoff,
splash cleanup will be called before any commit. This
will cause control path reset due to no bandwidth votes.
Add null commit during splash cleanup in case of panel
reconfiguration.

Change-Id: If500fdfb3913726d4d8462d38c200797256b4f46
Signed-off-by: Venkata Prahlad Valluru <vvalluru@codeaurora.org>