drm: msm: sde: update display status after handoff is done

Each displays's splash status should be set to false after
splash handoff is done, this will avoid potential display risk
when display output is configured again.

CRs-Fixed: 2251770
Change-Id: I62733cb1bcd52e584766349465047e466f211f82
Signed-off-by: Guchun Chen <guchunc@codeaurora.org>