mei: hdcp: Constify struct mei_cl_device_id

mei: hdcp: Constify struct mei_cl_device_id

mei_hdcp_tbl[] is never modified and can be made const to allow the
compiler to put it in read-only memory.

Before:
   text    data     bss     dec     hex filename
  15844    5416       0   21260    530c drivers/misc/mei/hdcp/mei_hdcp.o

After:
   text    data     bss     dec     hex filename
  16004    5256       0   21260    530c drivers/misc/mei/hdcp/mei_hdcp.o

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200610224704.27082-4-rikard.falkeborn@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>