pc: ACPI BIOS: replace template copying with ASL like macros

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
pc: ACPI BIOS: fix incorrect integer encoding for 0x{F-1}FFFF values

Fix typo in build_append_int() which causes integer
truncation when it's in range 0x{F-1}FFFF by packing it
as WordConst instead of required DWordConst.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
mv some code to helper funcs

Signed-off-by: Igor Mammedov <imammedo@redhat.com>