net: enetc: dynamically allocate rxmsg based on VF count

net: enetc: dynamically allocate rxmsg based on VF count

The constant ENETC_MAX_NUM_VFS is defined as 2 when enabling support for
LS1028A. This works for LS1028A because its ENETC hardware supports up
to 2 VFs. However, ENETC v4 has varying VF capabilities depending on the
SoC:

i.MX94 standalone ENETC: 0 VFs
i.MX94 internal ENETC:   3 VFs
i.MX952:                 1 VF

Using a fixed ENETC_MAX_NUM_VFS for memory allocation leads to
over-allocation on SoCs with fewer or no VF support. To better match
hardware capabilities and avoid unnecessary memory usage, change rxmsg
memory allocation from a fixed-size array to dynamic allocation based
on the actual VF count retrieved via pci_sriov_get_totalvfs().

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260522092438.1264020-13-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>