defconfig: msm8974: Enable the modem subsystem restart driver

Enable the modem subsystem restart driver; this driver monitors
the modem watchdog interrupt and the SMSM state and restarts
either the chip or just the modem when there is an error condition
detected.

Change-Id: I52d9c784e091cc9be89059743db0274faa2c40d0
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>