virtio: 1.0 helper to read 16/32/64 bit value
virtio: 1.0 helper to read 16/32/64 bit value

To avoid cluttering the driver code with modern/legacy code introduce
virtio_cpu_to_modern{16,32,64} and virtio_modern{16,32,64}_to_cpu in a
separate header file virtio-internal.h.

Signed-off-by: Nikunj A Dadhania <e2f4a5db9b4735182a88051d1e7a3599f9eac9db@linux.vnet.ibm.com>
Suggested-by: Thomas Huth <9e65be74847981e55b2564b6266c57d86d3bac05@redhat.com>
Reviewed-by: Thomas Huth <9e65be74847981e55b2564b6266c57d86d3bac05@redhat.com>
Signed-off-by: Alexey Kardashevskiy <ac1fc56530d7d037e1ea666f130daca22d72f964@ozlabs.ru>
Signed-off-by: Nikunj A Dadhania <e2f4a5db9b4735182a88051d1e7a3599f9eac9db@linux.vnet.ibm.com>

open-power-host-os/slof,open-power-host-os/slof,open-power-host-os/slof,open-power-host-os/slof