soc/intel_asdp: Unify misc. initialization registers

These two register blocks are defined in the platform layers, but
never change (except on 1.5 where they don't exist).  I don't want to
write a full devicetree interface for them as I can't find good docs
currently.  They are used only at system initialization, so move the
definitions to the single file where they're used.  In the longer term
we will want to move at least the GPDMA setup into a driver anyway.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>