USB: phy: fsl-usb: remove sysfs abuse

This file has a HUGE debugging sysfs file that spews out a lot of
information all at once, which violates the one-value-per-file rule for
sysfs.  If this is really needed, it should go into debugfs, but given
the age of this driver, I strongly doubt anyone is using it anymore.

So just remove the file entirely, it was never documented, so obviously,
no one actually needed it :)

Cc: Felipe Balbi <balbi@kernel.org>
Reviewed-by: Ran Wang <ran.wang_1@nxp.com>
Link: https://lore.kernel.org/r/20200702072914.1072878-1-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>