usb: gadget: pch_udc: fix an Excess kernel-doc warning

Delete one extraneous line of kernel-doc to prevent a kernel-doc
warning:

pch_udc.c:297: warning: Excess struct member 'desc' description in 'pch_udc_ep'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Cc: tomoya-linux@dsn.lapis-semi.com
Link: https://lore.kernel.org/r/20240115003008.5763-1-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>