clk: msm: mdss: Increase polling timer before SW calibration

Before completing SW calibration of HDMI PLL on
msm8996 v2, poll C READY register for an increased
period to ensure that we do not mistakenly perform
software calibration when it is not needed.

Change-Id: I7ec25665700ecf20b9fe2337eb01015b1e156b9b
Signed-off-by: Casey Piper <cpiper@codeaurora.org>