msm: mdss: remove bwc workaround for thulium

HW problem where panic was being asserted
continuously when BWC was enabled and causing
CPU throttling is fixed in thulium, so this
patch disables BWC workaround for this target.

Change-Id: Ie418dcfb75c6af06f3cdfe530da7d78e5d6c8ca8
Signed-off-by: Ingrid Gallardo <ingridg@codeaurora.org>