target: msm8996: Implement apis for early domain

Implement APIs for early-services to communicate
with the kernel running in parallel. Early services
use the apis by passing a service-id given to them.
They update their running status in a shared page
between lk & kernel through these apis, so kernel
can free the reserved resources.

Add supportive changes needed for the apis to
work.

Change-Id: Idece680e6fd82406aae6425464b741377cbabc9f
Signed-off-by: Vivek Kumar <vivekuma@codeaurora.org>