msm: mdss: Perform bandwidth check before applying any fudge

Earlier the bandwidth check is done after applying an ib_fudge.
This causes some valid use cases to fall back to GPU. Perform
bandwidth check against the actual value without considering
any fudges.

Change-Id: I09d10724c473c76ade8cf2a2b8d1bda9862816a2
Signed-off-by: Anusha Koduru <kanusha@codeaurora.org>