Move acpi code out of rombios32.c; clean up use of fixed memory addresses.

Move acpi code out of rombios32.c; clean up use of fixed memory addresses.

Move acpi code from rombios32.c to acpi.c.
Move all fixed memory addresses used by the code to config.h and
    consistently use a "BUILD_" prefix on the definitions.
Move some pci defs to pci.h - allows access from acpi.c and rombios32.c.
Introduce ALIGN() macro - remove old align function.