USB: gadget: Use Zero Interrupt Threshold Control for ci13xxx_msm

ITC (Interrupt Threshold Control) field is to set the maximum rate at
which the device controller will issue interrupts.  The maximum interrupt
interval is measured in micro frames.  Valid values are 0, 1, 2, 4, 8, 16,
32, 64.  The default value is 8 micro frames.  Set ITC to zero for MSM to
gain performance.

Change-Id: Idc383ffc9bc48b3681304b0f83e17a4cd39fb138
Signed-off-by: Anji jonnala <anjir@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>