ehci: portwise configurations

OMAP3 EHCI has three ports and we can configure port modes
(PHY/TLL) on per port basis in silicon version ES3.0 onwards.

This patch modifies the existing EHCI driver to accomodate
portwise mode configuration.

Changes being done:

        - Pass platform_data pointer as parameter to usb_ehci_init()
          to avoid multiple parameters.
        - Use platform_data pointer in usb-ehci.c as platform_data
          directly without copying it to another *pdata*.
        - Initializing platform_data in all platform files with
          platform specific ehci parameters.
        - Added port_mode[OMAP_HS_USB_PORTS]in platform_data
          structures.This allows to setup mux pins on per port basis.
        - Added phy_reset_gpio[OMAP_HS_USB_PORTS].

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