via-rhine: initial commit of the via-rhine driver for RHEL7

Backported from kernel-3.10.50

Signed-off-by: Philip J Perry <phil@elrepo.org>
via-rhine: define CONFIG_VIA_RHINE_MMIO to allow MMIO instead of PIO

This allows the driver to use PCI shared memory (MMIO) instead of
programmed I/O ports (PIO). Enabling this gives an improvement in
processing time in parts of the driver.

Signed-off-by: Philip J Perry <phil@elrepo.org>