usb: common: use of_property_read_bool()

Use more compact of_property_read_bool() calls for the boolean properties
instead  of of_find_property() calls  in of_usb_host_tpl_support() and
of_usb_update_otg_caps().

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>