clk: sunxi-ng: Constify struct ccu_reset_map

'struct ccu_reset_map' are not modified in these drivers.

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

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   1533	   2224	      0	   3757	    ead	drivers/clk/sunxi-ng/ccu-sun20i-d1-r.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   1597	   2160	      0	   3757	    ead	drivers/clk/sunxi-ng/ccu-sun20i-d1-r.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://patch.msgid.link/44745f27034fa670605cd16966a39b7fe88fe5a6.1726863905.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Chen-Yu Tsai <wens@csie.org>