Merge branch 'net-ftgmac100-support-fixed-link'

Tao Ren says:

====================
net: ftgmac100: support fixed link

The patch series adds fixed link support to ftgmac100 driver.

Patch #1 adds fixed link logic into ftgmac100 driver.

Patch #2 enables mac3 controller in Elbert dts: Elbert mac3 is connected
to the onboard switch BCM53134P's IMP_RGMII port directly (no PHY
between BMC MAC and BCM53134P).
====================

Link: https://lore.kernel.org/r/20220907054453.20016-1-rentao.bupt@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>