Probe of mem-buf device fails unless this property is present.
Fixes: c811ad67a6 ("ARM: dts: msm: Add support for mem-buf-msgq between oemvm and pvm")
Change-Id: I8ec7302fb79f554edf20e55b2d15ae61486f6d0c
Signed-off-by: Patrick Daly <quic_pdaly@quicinc.com>