davinci: Configure MDIO pins for EMAC

Earlier patch which adds EMAC support for da850/omap-l138
was not configuring the MDIO pins.

Ethernet was working fine with the earlier patch, because
the MDIO pins were configured from the boot loader. This
patch removes that dependency.

Also, this patch populates a member in the emac clk structure
to say that EMAC LPSC sits on controller 1.

Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>