usb: chipidea: removing of_find_property

call to of_find_property() before of_property_read_u32() is unnecessary.
of_property_read_u32() anyway calls to of_find_property() only.

Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>