Revert "powerpc/usb: fix issue of CPU halt when missing USB PHY clock"

This reverts commit 529febee.

To quote Dirk:
	This commit introduces a check for the USB PHY clock.
	Problem is that CTRL_PHY_CLK_VALID bit seems not to be present
	on all Freescale ehci implementations, at least P1022 does not
	have it.  So this check always fails and the driver never gets
	loaded.

So we need to revert this patch.

Reported-by: Dirk Eibach <Eibach@gdsys.de>
Cc: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>