disp: msm: sde: Use platform independent API for 64-bit div

64-bit division( operator "/") on 32-bit platforms is not supported.
Using platform independent API's here.

Change-Id: I1ec71ac120bb29b7f0bceed581b979606f81e2a5
Signed-off-by: Ravikanth Tuniki <rtunik@codeaurora.org>