intel PCI ops: Remove explicit PCI MMCONF access

MMCONF was explicitly used here to avoid races of 0xcf8/0xcfc access
being non-atomic and/or need to access 4kiB of PCI config space.

All these platforms now have MMCONF_SUPPORT_DEFAULT.

I liked the style of code in pci_mmio_cfg.h more, and used those to
replace the ones in io.h.

Change-Id: Ib5e6a451866c95d1edb9060c7f94070830b90e92
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/17689
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
6 files changed