clk: msm: mdss: increase VCO frequency to above 8.9Ghz

For some resolutions on MSM8996 V2, PLL can become
unlocked at high operating temperatures. To prevent
this, use a VCO frequency of at least 8.9Ghz for bit
clocks of at least 282Mhz.

Change-Id: I409f286d23a924eab8bcd204638602e530597d77
Signed-off-by: Casey Piper <cpiper@codeaurora.org>