msm: defconfig: Enable FastRPC driver

Enable CONFIG_MSM_ADSPRPC to allow communication with remote DSP
processors.

Change-Id: I7628e9b6537c4275d57e77da3a20f5291d1ee37b
Acked-by: Bharath Kumar <bkumar@qti.qualcomm.com>
Signed-off-by: Sathish Ambley <sathishambley@codeaurora.org>