ARM: dts: msm: Add support for RTB on mdmcalifornium

Enable RTB tracing support on mdmcalifornium. This change
adds size of memory to be reserved during RTB probe.

CRs-Fixed: 958591
Change-Id: I03cde22c68c0947d3543e8ec6dac74a08f1408bb
Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>