All x86 boards have so far set a custom heap memory pool size because of
their dependency on ACPI. It makes more sense to introduce a new
ACPI-specific option, utilizing the recently added
HEAP_MEM_POOL_ADD_SIZE_ Kconfig option prefix, and adjust the default
value as necessary for each board.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
