usb: xhci-mtk: check hcc_params after adding primary hcd

hcc_params is set in xhci_gen_setup() called from usb_add_hcd(),
so checks the Maximum Primary Stream Array Size in the hcc_params
register after adding primary hcd.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>