usb-storage: Constify struct usb_device_id and us_unusual_dev

'struct usb_device_id' and 'struct us_unusual_dev' are not modified in
these drivers.

Constifying these structures moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers (which is the case for struct us_unusual_dev).

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  25249	   4261	    896	  30406	   76c6	drivers/usb/storage/alauda.o
   3969	    672	    360	   5001	   1389	drivers/usb/storage/cypress_atacb.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  25461	   4041	    896	  30398	   76be	drivers/usb/storage/alauda.o
   4225	    400	    360	   4985	   1379	drivers/usb/storage/cypress_atacb.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/b1b75a2a64b1f6cfad2a611f71393f281178fd3f.1724507157.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>