drm: msm: sde: Update splash handoff with new APIs

Early domain core driver provides apis to communicate
with LK. Deprecate the use of scratch registers, instead
use the new apis. Early domain core driver now hot adds
the cpu and frees lk text section by taking vote from
all early serivces, So remove hot-adding cpu and freeing
lk text section from display.

Change-Id: Id083850872bca0803e029a85f946c70b2ec5298e
Signed-off-by: Vivek Kumar <vivekuma@codeaurora.org>