net: enetc: relocate SR-IOV configuration helper for common PF support

net: enetc: relocate SR-IOV configuration helper for common PF support

Move enetc_sriov_configure() from enetc_pf.c to enetc_msg.c to prepare
for integrating enetc_msg.c into the enetc-pf-common driver, where it
will be shared between ENETC v1 and v4 PF drivers.

Since enetc_msg_psi_init() and enetc_msg_psi_free() are now only called
from enetc_sriov_configure() within the same file, make them static.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260522092438.1264020-4-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>