usb: xhci-msm-hsic: Set the interrupt moderation to 12000

Higher value allows xhci core to moderate interrupts resulting
in fewer interrupts from xhci core. This may result in better
overall power consumption during peak throughput. Hence set the
default HSIC interrupt moderation to 12000 (or 3ms interval).
Add MSM_HSIC_INT_MODERATION macro for this value.

Change-Id: Idbcccd1a5cf2d24fa5dc2fea52a4f371f8a2c4cf
Signed-off-by: Vamsi Krishna <vskrishn@codeaurora.org>