Revert "mfd: Add omap-usbhs runtime PM support"

This reverts commit 7e6502d5.

Oops are produced during initialization of ehci and ohci
drivers. This is because the run time pm apis are used by
the driver but the corresponding hwmod structures and
initialization is not merged. hence revering  back the
commit id 7e6502d5



Signed-off-by: Keshava Munegowda <keshava_mgowda@ti.com>
Reported-by: Luciano Coelho <coelho@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>