USB: isp116x: fix enumeration on boot

This patch removes the buffering of the status register.
USB core behavior has changed a bit and this buffering was not refreshed
at the right time.  The core got buffered old value of HCRHPORT and it
did not detect any devices on boot.

Signed-off-by: Anti Sullin <anti.sullin@artecdesign.ee>
Acked by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>