net: davinci_mdio: Fix typo mistake in calling runtime-pm api

By mistake (most likely a copy-paste), instead of pm_runtime_get_sync()
api, driver is calling pm_runtime_put_sync() api in resume callback
function. The bug was introduced by commit id (ae2c07aaf74:
davinci_mdio: runtime PM support).

Now, the reason why it didn't impact functionality is, the patch has
been tested on AM335x-EVM and BeagleBone platform while submitting;
and in case of AM335x the MDIO driver doesn't control the module
enable/disable part, which is handled by CPSW driver.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>