phy: cadence-torrent: Constify a u32[]

'cdns_torrent_refclk_driver_mux_table' is not modified in this driver.
And it is only used as a "const u32 *".

Constifying this structure moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  93578	   4798	     16	  98392	  18058	drivers/phy/cadence/phy-cadence-torrent.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  93606	   4790	     16	  98412	  1806c	drivers/phy/cadence/phy-cadence-torrent.o
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/34e23ceb6b7b7eb730ee8deee21d231b504dc65f.1720718240.git.christophe.jaillet@wanadoo.frSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/cadence/phy-cadence-torrent.c

@@ -285,7 +285,7 @@ static const int refclk_driver_parent_index[] = {
 	CDNS_TORRENT_RECEIVED_REFCLK
 };
 
-static u32 cdns_torrent_refclk_driver_mux_table[] = { 1, 0 };
+static const u32 cdns_torrent_refclk_driver_mux_table[] = { 1, 0 };
 
 enum cdns_torrent_phy_type {
 	TYPE_NONE,