Match PCI UART devices using PCI data from the ACPI SPCR table

[val_packett.cool]

Summary

(continuing from https://reviews.freebsd.org/D19507)

uart_bus_probe matches discovered devices to system devices using resource addresses (uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)).

The Amazon EC2 UART has different addresses in ACPI (0x90A0000) and PCI (0x80118000). Let's use the PCI address from the SPCR table to match PCIe UART devices.

This fixes userspace console logging (without an UART device, there's no tty, only kernel prints work).

Test Plan

Tested on EC2 a1 instances (ttyu1 appears only with the patch) and on ACPI systems with non-PCI UARTs like my MACCHIATObin desktop (no harm)

[emaste]

FYI if you put just the D19507 reference (not the full URL) in a comment Phabricator will create a cross-reference automatically.

[val_packett.cool]

Rebased for rS348195 (D20357)