usb: spear-ehci/ohci: Use devm_*() routines

This patch frees SPEAr ehci/ohci drivers from tension of freeing resources :)
devm_* derivatives of multiple routines are used while allocating resources,
which would be freed automatically by kernel.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>