usb: ohci: nxp: remove USB PLL and USB OTG clock management

LPC32xx common clock framework driver correctly manages parent clocks
of USB OHCI clock, so there is no need to manually enable and
disable them from the driver, which now depends only on a single USB
host clock.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>