net: fix fsl_pq_mdio driver to use module_init()

Modules are not supposed to use any of the *_initcall*() hooks as
the entry point.  fsl_pq_mdio.c was using subsys_initcall_sync()
instead of module_init() to guarantee that the MDIO bus was initialized
before the Ethernet driver goes looking for the phy.  However, the recent
OF helpers rework happens to also make sure PHY connection is deferred to
.open time, so using an initcall is no longer necessary.

This patch replaces the initcall with a more traditional an accepted
module_init() call.

Tested on Freescale MPC8349emitxgp eval board.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/fsl_pq_mdio.c

@@ -415,10 +415,10 @@ int __init fsl_pq_mdio_init(void)
 {
 	return of_register_platform_driver(&fsl_pq_mdio_driver);
 }
+module_init(fsl_pq_mdio_init);
 
 void fsl_pq_mdio_exit(void)
 {
 	of_unregister_platform_driver(&fsl_pq_mdio_driver);
 }
-subsys_initcall_sync(fsl_pq_mdio_init);
 module_exit(fsl_pq_mdio_exit);