USB: EHCI: msm: remove ehci_port_power() routine

Patch (as1623) removes the ehci_port_power() routine and all the
places that call it.  There's no reason for ehci-msm/hsic to change
the port power settings; the hub driver takes care of all that stuff.

Change-Id: I789a4a021d89ebd75f8e6232d1ba15a30f9f1944
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>