build: add an option to build INF files for Win10 as DIFX compatible
build: add an option to build INF files for Win10 as DIFX compatible

INF files for Win10 has 10.0 OS ornamentation that makes them
not installable with DIFX. Add a possibility to build INF files
for Win10 with 6.3 ornamentation by settinge environment
variable WIN10_INF_DIFX_COMPAT=1

Signed-off-by: Yuri Benditovich <9668326cb042de5d91fd7679dac7ca5ea402812c@daynix.com>

virtio-win/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,virtio-win/kvm-guest-drivers-windows,vrozenfe/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows,YanVugenfirer/kvm-guest-drivers-windows,daynix/kvm-guest-drivers-windows