net: fec: fix clock count mis-match

pm_runtime_put_autosuspend in probe will call runtime suspend to
disable clks automatically if CONFIG_PM is defined. (If CONFIG_PM
is not defined, its implementation will be empty, then runtime
suspend will not be called.)

Therefore, we can call pm_runtime_get_sync to runtime resume it
first to enable clks, which matches the runtime suspend. (Only when
CONFIG_PM is defined, otherwise pm_runtime_get_sync will also be
empty, then runtime resume will not be called.)

Then it is fine to disable clks without causing clock count mis-match.

Fixes: c43eab3e ("net: fec: add missed clk_disable_unprepare in remove")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>