usb: chipidea: host: fix NULL ptr dereference during shutdown

usb: chipidea: host: fix NULL ptr dereference during shutdown

After commit 4b7c4ef9b68c ("usb: chipidea: implement platform shutdown
callback") and commit bde98731e127 ("usb: chipidea: host: set host to
be null after hcd is freed") a NULL pointer dereference is caused
on i.MX23 during shutdown. So ensure that role is set to CI_ROLE_END and
we finish interrupt handling before the hcd is deallocated. This avoids
the NULL pointer dereference.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 4b7c4ef9b68c ("usb: chipidea: implement platform shutdown callback")
Signed-off-by: Peter Chen <peter.chen@nxp.com>