Since usb_endpoint_maxp now returns only lower 11 bits mult
calculation here isn't correct anymore and that breaks webcam
for me. Patch make use of usb_endpoint_maxp_mult instead of
direct calculation.
Fixes: abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return
only packet size")
Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>