ARM: dts: msm: Remove IB vote for DDR memory from Video

For MSM8994, IB vote for DDR memory has been deprecated.
Bus driver needs to consider only AB vote from video. This
change makes IB vote to '0' so that bus driver ignores IB.

Change-Id: Ie108e9ed8b2f8a663700044f26af1fd63add4e3e
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>