USB: isp1760: don't auto disable Port1 on ISP1761

There is no need to disable port 1 on ISP1761. That port could
be used as an OTG port which would require a different init
sequence. However we don't have OTG support (yet) so we can use
it as a normal USB port.
This patch allows port 1 to be used a normal Port on the ISP1761.

Signed-off-by: Thomas Hommel <Thomas.Hommel@gefanuc.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>