net: mana: Query device capabilities and configure MSI-X sharing for EQs

net: mana: Query device capabilities and configure MSI-X sharing for EQs

When querying the device, adjust the max number of queues to allow
dedicated MSI-X vectors for each vPort. The per-vPort queue count is
clamped towards MANA_DEF_NUM_QUEUES but will not exceed the hardware
maximum reported by the device.

MSI-X sharing among vPorts is enabled when there are not enough MSI-X
vectors for dedicated allocation, or when the platform does not support
dynamic MSI-X allocation (in which case all vectors are pre-allocated
at probe time and sharing is always used). The msi_sharing flag is
reset at the top of mana_gd_query_max_resources() so it is recomputed
from current hardware state on each probe or resume cycle.

Clamp apc->max_queues to gc->max_num_queues_vport in mana_init_port()
so that on resume, if max_num_queues_vport has decreased due to fewer
MSI-X vectors, num_queues is reduced accordingly before EQ allocation.

A device reporting zero ports now results in a fatal probe error since
the per-vPort MSI-X math requires at least one port.

Rename mana_query_device_cfg() to mana_gd_query_device_cfg() as it is
used at GDMA device probe time for querying device capabilities.

Signed-off-by: Long Li <longli@microsoft.com>
Link: https://patch.msgid.link/20260605005717.2059954-3-longli@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>