USB: EHCI: msm: Add platform device to support HSUSB core4 in Host Mode

Liquid platform on 8064 has ehci compliant HSUSB core4 to support
GOBI module via PCIe MINI Card CONNECTOR. This patch adds platform
device instance for EHCI compliant USB Host Controller driver.

Change-Id: I0d01babc3a818b308216bb57e48522cd2b62e07c
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>