i2c: piix4: Add EFCH MMIO support to region request and release

EFCH cd6h/cd7h port I/O may no longer be available on later AMD
processors and it is recommended to use MMIO instead. Update the
request and release functions to support MMIO.

MMIO request/release and mmapping require details during cleanup.
Add a MMIO configuration structure containing resource and vaddress
details for mapping the region, accessing the region, and releasing
the region.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
[wsa: rebased after fixup in previous patch]
Signed-off-by: Wolfram Sang <wsa@kernel.org>