defconfig: fsm9010: Add devtmpfs support

Support for devtmpfs is required on fsm9010 targets for udev.
The hotplug uevent is deprecated.

Change-Id: I86ecb1a9174c95fefbc328720386a3220dc9b0f7
Acked-by: Kaushik Sikdar <ksikdar@qti.qualcomm.com>
Signed-off-by: Venkatesh Yadav Abbarapu <quicvenkat@codeaurora.org>