when missing USB PHY clock, kernel booting up will halt during USB
initialization. We should check USBGP[PHY_CLK_VALID] bit to avoid
CPU hang in this case.
Signed-off-by: NShengzhou Liu <Shengzhou.Liu@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>