Currently if we bootup a device without cable connected, then
usb-conn-gpio won't call set_role() since last_role is same as
current role. This happens because during probe last_role gets
initialised to zero.
To avoid this, add a new flag initial_detection in the struct
usb_conn_info, which prevents from bailing out during initial
detection.
Fixes: 4602f3bff266 ("usb: common: add USB GPIO based connection detection driver")
Signed-off-by: Prashanth K <quic_prashk@xxxxxxxxxxx>