share/man/man4/Makefile: Only install Hyper-V man pages on amd64 and i386

We shouldn't install them on the architectures not supported by Hyper-V.

And, hv_ata_pci_disengage.4.gz should be removed from all architectures:

1. It should have only applied to Hyper-V;
2. For Hyper-V platforms (amd64 and i386), the related driver was removed by

r306426 | sephe | 2016-09-29 09:41:52 +0800 (Thu, 29 Sep 2016),
because now we have a better mechanism to disble the ata driver for hard
disks when the VM runs on Hyper-V.

Reviewed by: sephe, andrew, jhb
Approved by: sephe (mentor)
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8572