soc/intel_adsp: Unify boot loader memory layout

These values (used to arrange the bootloader within IMR memory) are
mostly computed or fixed to values that don't chagne between
platforms.  Only the manifest address and the location of the data
section change.  Put those in kconfig, move the rest to the global
header.

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