drivers: mm/intel_adsp: Add MMU support to MM driver

In the Intel platforms most of HPSRAM is used by modules when
are required. By default all these banks are powered off and are
enabled by L2 MM driver only when needed.

At the driver initialisation each unused page is unmaped and
when whole HPSRAM bank is unused the power is switched off.

Since mapping memory in MMU TLB and flushing it at system start is
not needed and time consuming, this patch modifies the init
sequence to avoid it.

Additionally it adds MMU maping and unmaping for pages allocated
from unused pool.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Signed-off-by: Jaroslaw Stelter <Jaroslaw.Stelter@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>