ARM: dts: msm: reserve memory for display ramdump for TRINKET

Reserve memory for display ramdump feature on trinket target.
This memory buffer would be configured by the bootloader and
needs to be retained forever.

Change-Id: Id1ce557e8692caac9b24c2cd26251e747ff608ca
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>