The innovator board needs a special case for its phy control.

Move the corresponding code into the board file and out of the
common code by adding another callback.
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>