power: supply: samsung-sdi-battery: Constify struct power_supply_vbat_ri_table

'struct power_supply_vbat_ri_table' are not modified in this driver.

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

In order to do it, some code also needs to be adjusted to this new const
qualifier.

On a x86_64, with allmodconfig:
Before:
======
$ size drivers/power/supply/samsung-sdi-battery.o
   text	   data	    bss	    dec	    hex	filename
    955	   7664	      0	   8619	   21ab	drivers/power/supply/samsung-sdi-battery.o

After:
=====
$ size drivers/power/supply/samsung-sdi-battery.o
   text	   data	    bss	    dec	    hex	filename
   4055	   4584	      0	   8639	   21bf	drivers/power/supply/samsung-sdi-battery.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/d01818abd880bf435d1106a9a6cc11a7a8a3e661.1719125040.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>