Documentation: update of USB_CHIPIDEA_DEBUG

[Valentin Rothberg <valentinrothberg@gmail.com>]

Hi Peter,

your commit 2fb2884ed856 ("usb: chipidea: delete static debug support")
has shown up in today's Linux next tree (i.e., next-20151102) and
removes the Kconfig option USB_CHIPIDEA_DEBUG in favor of dynamic debug
support.  However, there are some documentary references on this option
still left in the code that may need to be updated:

Documentation/usb/chipidea.txt-9-If you want to check some internal variables for otg fsm,
Documentation/usb/chipidea.txt:10:select CONFIG_USB_CHIPIDEA_DEBUG, there are 2 files which
                                         ^^^^^^^^^^^^^^^^^^^^^^^^^
Documentation/usb/chipidea.txt-11-can show otg fsm variables and some controller registers value:
--
drivers/usb/chipidea/core.c-25- * Compile Options
drivers/usb/chipidea/core.c:26: * - CONFIG_USB_CHIPIDEA_DEBUG: enable debug facilities
                                    ^^^^^^^^^^^^^^^^^^^^^^^^^
drivers/usb/chipidea/core.c-27- * - STALL_IN:  non-empty bulk-in pipes cannot be halted


I'm just pointing to those references, since I don't know if you want to
keep them in the code or not.  I found the issue and your commit with
scipts/checkkconfigsymbols.py.

Kind regards,
 Valentin