defconfig: sdxprairie: Enable subsystem firmware loader support

Enable Subsystem Restart (SSR) framework, sysmon, peripheral-loader (PIL),
the generic secure PIL driver and Secure Channel Manager (SCM) calling
convention. This enables the subsystem firmware power-on, shutdown, and
handling error-fatal functionalities.

Change-Id: Iddde20bc9d725b5e16996a2ee3a13d2938770787
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>