defconfig: sm8150: Enable MHI host driver stack

MHI Host Interface is a communication protocol to be used by the host
to control and communicate with modem over a high speed peripheral bus.
Enabling this stack will allow host to communicate with external devices
that support MHI protocol.

CRs-Fixed: 2204910
Change-Id: I856b035d196885420797594e3c274390b5504237
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>