msm: apr: initialize subsystem device state early

The current APR driver initializes subsystem state from late_init so
slimbus driver reads ADSP's state too late.
Move initialization code to apr_init so that slimbus driver can be
probe sooner.

Change-Id: I14d1bf294b40dd7ea184923ba023646e05912fff
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>