msm: mdss: fix to update the correct panel info for dynamic fps

Current code does not reflect the correct panel information
when user space request the panel info and fps data after
the fps update.
This change fix the code, so further calls to get the
screen info have the correct panel data.

Change-Id: I3e0382748cbf8b480c2516223cfe14444d388e29
Signed-off-by: Ingrid Gallardo <ingridg@codeaurora.org>