ARM: dts: msm: disable mdss-fb memory of apq8096 drone

Disable the mdss-fb memory which has been reserved in apq8096 drone.
90M memory space will be saved.

Change-Id: I2e9d969c4957938f59048eb231e53b4855b33a00
CRs-Fixed: 1105520
Signed-off-by: Haihe Zhang <haihez@codeaurora.org>