soc: intel_adsp: ace: Use DT macros instead of hardcoded values

Replace hardcoded register addresses and values in
asm_memory_management.h with Devicetree (DT) macros for LPSRAM
power-down operations. This change ensures that register addresses and
bank counts are dynamically obtained from the Devicetree, improving code
portability and reducing the risk of errors due to manual updates.

- Removed hardcoded LSPGCTL address definitions.
- Updated m_ace_lpsram_power_down_entire macro to use DT_NODELABEL to
  fetch LPSRAM bank count and control register address
- Adjusted bit field extraction logic to align with the updated register
  information from the Devicetree.

This commit aligns with the ongoing effort to utilize Devicetree for
hardware abstraction and to facilitate easier maintenance and updates to
the codebase.

Signed-off-by: Tomasz Leman <tomasz.m.leman@intel.com>