net: ethernet: mediatek: fix missing changes merged for conflicts overlapping commits

add the missing commits about
1)
Commit d3bd1ce4
("remove redundant free_irq for devm_request_ir allocated irq")
2)
Commit 7c6b0d76
("fix logic unbalance between probe and remove")

during merge for conflicts overlapping commits by
Commit b20b378d
("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net"

)

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>