OMAPDSS: DSS: Fixing display's state-machine for suspend

Issue with entering blaze to suspend state fixed.
Also fixed error during hdmi driver resume when actual
hdmi device was not connected.

Change-Id: Iffb151982f020afb40dc2b39b35aa80a03091b32
Signed-off-by: Andrii Guriev <x0160204@ti.com>