PCI: add more checking to ICH region quirks

Per ICH4 and ICH6 specs, ACPI and GPIO regions are valid iff ACPI_EN
and GPIO_EN bits are set to 1. Add checks for these bits into the
quirks prior to the region creation.

While at it, name the constants by macros.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>