msm: mdp3: reduce mdp3 clk scaling levels

Having more number of clk scaling levels is resulting in lower
mdp clk in some usecases leading to power regression. Reduce
the no: of clk levels so that the mdp clk remains at the correct
value for all usecases.

Change-Id: Idc8711f24f2e2ca72aa15bba9ad60c622172a378
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>