acpi: PCI routing DSDT simplifications.

acpi: PCI routing DSDT simplifications.

Use define_link() macro in PIIX4 hardware definitions.  Now that all
remaining irq links are the same it's possible to just use a macro to
define the link.

Port several size optimizations to the q35 irq routing definitions:
define the PRQx fields in the _SB scope to reduce size of register
references, define CRS and STA methods in _SB scope to reduce code
duplication, simplify acpi code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>