ARM: dts: msm: disable bwc for msm8994

Rotator bandwidth compression (BWC) is causing performance issues on
msm8994. Disable it until root cause is sorted out.

Change-Id: I2673863bed58dc1c47bfa5a167e308508d581bcd
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>