usb: chipidea: need to mask INT_STATUS when write otgsc

For otgsc, both enable bits and status bits are in it. So we need
to make sure the status bits are not be cleared when write enable
bits. It can fix one bug that we plug in/out Micro AB cable fast,
and sometimes, the IDIS will be cleared wrongly when handle last
ID interrupt (ID 0->1), so the current interrupt will not occur.

For stable tree: 3.12+

Cc: stable@vger.kernel.org
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>