usb: hub: Fix enumration timeout

usb: hub: Fix enumration timeout

Patch b6d7852c increases timeout for enumeration, taking
worst case to be 10 sec.
get_timer() api returns timestamp in milliseconds, which is
what we are checking in the do-while() loop in usb_hub_configure()
(get_timer(start) < CONFIG_SYS_HZ * 10).
This should give us a required check for 10 seconds, and thereby
we don't need to add additional mdelay of 100 microseconds in
each cycle.

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Reviewed-by: Vipin Kumar <vipin.kumar@st.com>