ARM: dts: msm: Add GPU PIL for Zap shader on msmtitanium

GPU uses a zap shader ucode to flush internal memories when
switching from trusted to untrusted mode. This ucode needs to be
protected and programmed by the TZ. We use the PIL to do
the appropriate calls to the TZ for us and it needs a DT node
to recognize what needs to be loaded.

Change-Id: I83c06c86d41995cccc63b8283c589eea68fbb629
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>