wifi: rtlwifi: Constify struct rtl_hal_ops and rtl_hal_cfg

wifi: rtlwifi: Constify struct rtl_hal_ops and rtl_hal_cfg

'struct rtl_hal_ops' and 'struct rtl_hal_cfg' are not modified in these
drivers.

Constifying this structure moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.

Constification of rtl_hal_cfg is only needed in rtl8192cu/sw.c

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  10167	   5512	    128	  15807	   3dbf	drivers/net/wireless/realtek/rtlwifi/rtl8188ee/sw.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  10743	   4936	    128	  15807	   3dbf	drivers/net/wireless/realtek/rtlwifi/rtl8188ee/sw.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/2c3f3d8d8b2f7dcb8cc64cebe89e55720d1d733d.1747500351.git.christophe.jaillet@wanadoo.fr