Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges

vmbus_sendpacket_mpb_desc() is currently used only by the storvsc driver
and is hardcoded to create a single GPA range. To allow it to also be
used by the netvsc driver to create multiple GPA ranges, no longer
hardcode as having a single GPA range. Allow the calling driver to
specify the rangecount in the supplied descriptor.

Update the storvsc driver to reflect this new approach.

Cc: <stable@vger.kernel.org> # 6.1.x
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://patch.msgid.link/20250513000604.1396-2-mhklinux@outlook.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>