x86/PCI: Make broadcom_postcore_init() check acpi_disabled

acpi_os_get_root_pointer() may return a valid address even if acpi_disabled
is set, but the host bridge information from the ACPI tables is not going
to be used in that case and the Broadcom host bridge initialization should
not be skipped then, So make broadcom_postcore_init() check acpi_disabled
too to avoid this issue.

Fixes: 6361d72b04d1 (x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan)
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Linux PCI <linux-pci@vger.kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/3186627.pxZj1QbYNg@aspire.rjw.lan
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/pci/broadcom_bus.c

@@ -97,7 +97,7 @@ static int __init broadcom_postcore_init(void)
 	 * We should get host bridge information from ACPI unless the BIOS
 	 * doesn't support it.
 	 */
-	if (acpi_os_get_root_pointer())
+	if (!acpi_disabled && acpi_os_get_root_pointer())
 		return 0;
 #endif