Add support for xhci in Armada 3700 and 7k/8k
This driver will be used by Marvell Armada 3700 and 7k/8k SoC families.
The same, generic xhci device also appears in Armada 380, so we are reusing
driver.
This patch also adds xhci_mv.c entry to the arm64 files list.
Submitted by: Patryk Duda <pdk@semihalf.com>
Obtained from: Semihalf
Sponsored by: Semihalf
Differential Revision: https://reviews.freebsd.org/D12252