msm: mdss: apply bus throughput factor for high downscale cases

For downscaling a 32 BPP surface with scale ratio greater than
or equal to 3.5, it is recommended to increase the mdp core clock
by 10%. This is to avoid any stalls on the bus during high concurreny
scenarios.

Change-Id: I77c8c25c73e4232271a93397e52798a6d5d74cf3
Signed-off-by: Krishna Chaitanya Devarakonda <kdevarak@codeaurora.org>