drivers: memc: Fix various APS6404 device issues

This commit deals with fixing various issues that prevents
the device from being built. In specific:

1. Fix default timing macro definitions to build with
an MSPI controller, other than AMBIG.
Add macro definition for MSPI_PORT.
2. Timing settings should be applied only when MSPI_TIMING
is defined. Otherwise, the APS6404 initialization routine
will fail with -EIO.
3. Similarly, use MSPI_XIP and MSPI_SCRAMBLE to apply XIP
and SCRAMBLE device settings, respectively (optimization).
4. MEMC_INIT_PRIORITY is assigned higher priority than
MSPI_INIT_PRIORITY which results in compiler error as
APS6404 device initialization depends on its underlying
MSPI bus controller.
5. The 'acquire' subroutine should be compiled when PM_DEVICE
is used (suppress compiler warning).

Signed-off-by: Ioannis Karachalios <ioannis.karachalios.px@renesas.com>