ehci: Support for ES3.x

OMAP ES3.x supports portwise PHY or TLL mode of operation whereas
in ES2.x all the three ports can either be in PHY mode or in TLL
mode.Port3 can not be configured in PHY mode.

Port mode must be defined either PHY, TLL or UNKNOWN in platform
files.Be careful of the scenario where one port is set as PHY and
other in TLL but the OMAP silicon version is 2.x or earlier where
this scenario is *not* supported.

Changes are :
        - Setup all the bypass configuration in omap_start_ehc()
          based on ES version.
        - Remove UHH_HOSTCONFIG programming for bypass settings
          in omap_usb_utmi_init()

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>