As I was pretty sure that the 3.x kernel had been built without those kernel modules I had a quick "play" with
make menuconfig on the 3.x
kernel sources: When selecting 'Device Drivers' and after enabling and then selecting 'Staging Drivers' I had to disable 'Exclude Staging drivers from beeing built', before I could go down and enable 'Microsoft Hyper-V client drivers'.
With this changed configuration (which essentially makes the following few changes
CONFIG_STAGING=y
CONFIG_HYPERV=m
CONFIG_HYPERV_STORAGE=m
CONFIG_HYPERV_BLOCK=m
CONFIG_HYPERV_NET=m
in the '.config' file) one should be able (at least in theory) to build the missing modules.
I for one neither have access to a Hyper-V system, nor the inclination to test this out, so all this is purely a theoretical excercise for me. I therefore have no idea what else might be missing.